Efficient and rapid generation of neural stem cells by direct conversion of fibroblasts with single microRNAs.

Neural stem cells (NSCs) hold great potential in neurodegenerative disease therapy, drug screening, and disease modeling. However, current approaches for induced NSCs (iNSCs) generation from somatic cells are still slow and inefficient. Here we report the establishment of a rapid and efficient method of iNSCs generation from human and mouse fibroblasts by using single microRNAs (miR-302a).

The reward and penalty for ozone pollution control caused by natural sources and regional transport: A case study in Guangdong province.

Ground-level O pollution in the Pearl River Delta region (PRD) is closely related to anthropogenic, natural emissions and regional transport. However, the interactions among different sources and natural intervention in modulating anthropogenic management have not been comprehensively assessed. Here, the WRF-CMAQ-MEGAN modeling system was utilized to simulate an O episode over PRD.

Explainable ensemble machine learning revealing the effect of meteorology and sources on ozone formation in megacity Hangzhou, China.

Megacity Hangzhou, located in eastern China, has experienced severe O pollution in recent years, thereby clarifying the key drivers of the formation is essential to suppress O deterioration. In this study, the ensemble machine learning model (EML) coupled with Shapley additive explanations (SHAP), and positive matrix factorization were used to explore the impact of various factors (including meteorology, chemical components, sources) on O formation during the whole period, pollution days, and typical persistent pollution events from April to October in 2021-2022. The EML model achieved better performance than the single model, with R values of 0.

Comparative analysis for the impacts of VOC subgroups and atmospheric oxidation capacity on O based on different observation-based methods at a suburban site in the North China Plain.

The persistent O pollution in the Beijing-Tianjin-Hebei (BTH) region remains unresolved, largely due to limited comprehension of O-precursor relationship and photochemistry drivers. In this work, intraday O sensitivity evolution from VOC-limited (volatile organic compound) regime in the forenoon to transition regime in the late afternoon was inferred by relative incremental reactivity (RIR) in summer 2019 at Xianghe, a suburban site in BTH region, suggesting that VOC-focused control policy could combine with stringent afternoon NO control. Then detailed impacts of VOC subgroups on O formation were further comprehensively quantified by parametric OH reactivity (K), O formation potential (OFP), as well as RIR weighted value and O formation path tracing (OFPT) approach based on photochemical box model.

Exploring formation mechanism and source attribution of ozone during the 2019 Wuhan Military World Games: Implications for ozone control strategies.

A series of emission reduction measures were conducted in Wuhan, Central China, to ensure good air quality during the 7th Military World Games (MWG) in October 2019. To better understand the implications for ozone (O) pollution control strategies, we applied integrated analysis approaches based on the de-weathered statistical model, parameterization methods, chemical box model, and positive matrix factorization model. During the MWG, concentrations of O, NO, and volatile organic compound (VOCs), OFP (O formation potential), L (OH radical loss rate) were 83 µg/m, 43 µg/m, 26 ppbv, 188 µg/m, and 3.

Long-term variation, solubility and transport pathway of PM-bound iron in a megacity of northern China.

Although particulate Fe has a significant impact on human health, atmospheric chemical reactions, air quality, climate change, and ecosystems, there is a lack of long-term continuous hourly observation on particulate Fe in the megacity of Beijing, limiting research on these issues. To address this gap, this study continuously measured hourly concentrations of Fe in PM from October 2018 to October 2022 in Beijing. The results indicate an overall decline in Fe concentrations, consistent with previous studies in Beijing.

Vertical distribution of VOCs in the boundary layer of the Lhasa valley and its impact on ozone pollution.

To investigate the vertical distribution of volatile organic compounds (VOCs) concentrations in the Lhasa valley region, an intensive measurement campaign was first conducted in summer using a tethered balloon. The results showed that the average concentration of surface VOCs was 49.1 ± 30.

[Variations in Ozone Concentration in Seven Regions Under Different Temperature and Humidity Conditions].

In recent years, the situation of ozone pollution in China has become increasingly severe, with PM being the main pollutant in the atmospheric environment of several cities. Meteorological conditions, particularly temperature and humidity, have a great influence on ozone formation. Therefore, understanding and quantifying the impact of the variation in temperature and humidity on ozone level can effectively provide the theoretical basis for the government to prevent and control ozone pollution.

Analysis of severe ozone-related human health and weather influence over China in 2019 based on a high-resolution dataset.

Ozone pollution in 2019 in China is particularly severe posing a tremendous threat to the health of Chinese inhabitants. In this study, we constructed a more reliable and accurate 1-km gridded dataset for 2019 with as many sites as possible using the inverse distance weight interpolation method to analyze spatiotemporal ozone pollution characteristics and health burden attributed to ozone exposure from the perspective of different diseases and weather influence. The accuracy of this new dataset is higher than other public datasets, with the coefficient of determination of 0.

Significant roles of aged dust aerosols on rapid nitrate formation under dry conditions in a semi-arid city.

Mineral dust can accelerate secondary aerosol formation under humid conditions. However, it is unclear whether it can promote secondary aerosol formation under dry conditions. To investigate this issue, two years of comprehensive observations was conducted at a semi-arid site, near the dust source regions.

[Seasonal Variations and Source Apportionment of Carbonaceous Components in Luoyang: Implication for Brown Carbon Contribution].

A total of 98 samples were collected to analyze the seasonal variation and source apportionment of carbonaceous components, especially brown carbon (BrC), of PMin Luoyang during 2018-2019. The concentrations of organic carbon (OC) and elemental carbon (EC) ranged from (7.04±1.

The urgent need to control volatile organic compound pollution over the Qinghai-Tibet Plateau.

Owing to the impact of the western development of China, there have been signs of air pollution over the Qinghai-Tibet Plateau in recent years. However, monitoring data on atmospheric volatile organic compounds (VOCs) are lacking in plateau areas. Here, VOCs concentrations in urban and background areas in North China and the Qinghai-Tibet Plateau were observed from 2012 to 2014 and 2020 to 2022, respectively.

Significant coal combustion contribution to water-soluble brown carbon during winter in Xingtai, China: Optical properties and sources.

To understand the characteristics of atmospheric brown carbon (BrC), daily PM samples in Xingtai, a small city in North China Plain (NCP), during the four seasons of 2018-2019, were collected and analyzed for optical properties and chemical compositions. The light absorption at 365 nm (abs) displayed a strong seasonal variation with the highest value in winter (29.0±14.

Significant decline in aerosols in the mixing layer in Beijing from 2015 to 2020: Effects of regional coordinated air pollution control.

Beijing's air quality has improved significantly since the implementation of the Air Pollution Prevention and Control Action Plan in 2013, but the local and regional contributions to this improvement have rarely been studied. Here, the vertical profile of the atmospheric backscattering coefficient (ABC) was measured by a ceilometer in Beijing from 2015 to 2020. The results show that the ABC in Beijing decreased the most at ground level from 2015 to 2020, decreasing 51.

The environmental benefit of Beijing-Tianjin-Hebei coal banning area for North China.

In order to achieve the targets specified in the Action Plan for Air Pollution Prevention and Control (APAPPC), a limited coal banning area (10,000 km) was designated in the heavily polluted Beijing-Tianjin-Hebei region (BTH) for the first time in 2017. PM and elements were sampled by the network of BTH to evaluate the effectiveness of this policy. This study found that the fine days with PM < 75 μg m accounted for 74.

Significant reduction in atmospheric organic and elemental carbon in PM in 2+26 cities in northern China.

To better understand the change characteristics and reduction in organic carbon (OC) and elemental carbon (EC) in particulate matter (PM) with a diameter of ≤2.5 μm (PM) driven by the most stringent clean air policies and pandemic-related lockdown measures in China, a comprehensive field campaign was performed to measure the carbonaceous components in PM on an hourly basis via harmonized analytical methods in the Beijing-Tianjin-Hebei and its surrounding region (including 2 + 26 cities) from January 1 to December 31, 2020. The results indicated that the annual average concentrations of OC and EC reached as low as 6.