Atmospheric CO2 in the megacity Hangzhou, China: Urban-suburban differences, sources and impact factors.

Limited observation sites and insufficient monitoring of atmospheric CO2 in urban areas restrict our comprehension of urban-suburban disparities. This research endeavored to shed light on the urban-suburban differences of atmospheric CO2 in levels, diurnal and seasonal variations as well as the potential sources and impact factors in the megacity of Hangzhou, China, where the economically most developed region in China is. The observations derived from the existing Hangzhou Atmospheric Composition Monitoring Center Station (HZ) and Lin'an Regional Atmospheric Background Station (LAN) and the newly established high-altitude Daming Mountain Atmospheric Observation Station (DMS), were utilized. From November 2020 to October 2021, the annual averages of HZ, LAN and DMS were 446.52 ± 17.01 ppm, 441.56 ± 15.42 ppm, and 422.02 ± 10.67 ppm. The difference in atmospheric CO2 mole fraction between HZ and LAN was lower compared to the urban-suburban differences observed in other major cities in China, such as Shanghai, Nanjing, and Beijing. Simultaneous CO2 enhancements were observed at HZ and LAN, when using DMS observations as background references. The seasonal variations of CO2 at LAN and DMS exhibited a high negative correlation with the normalized difference vegetation index (NDVI) values, indicating the strong regulatory of vegetation canopy. The variations in boundary layer height had a larger influence on the low-altitude HZ and LAN stations than DMS. Compared to HZ and LAN, the atmospheric CO2 at DMS was influenced by emissions and transmissions over a wider range. The potential source area of DMS in autumn covered most areas of the urban agglomeration in eastern China. DMS measurements could provide a reliable representation of the background level of CO2 emissions in the Yangtze River Delta and a broader region. Conventional understanding of regional CO2 level in the Yangtze River Delta through LAN measurements may overestimate background concentration by approximately 10.92 ppm.

Super blinking and biocompatible nanoprobes based on dye doped BSA nanoparticles for super resolution imaging.

As one of the super-resolved optical imaging techniques, single molecule localization microscopy (SMLM) received considerable attention due to its impressive spatial resolution. Compared with other fluorescence imaging techniques, SMLM has one particular request for the fluorophores, that is, continuous 'on' and 'off' behaviors of their signals (referred to as 'blinking'). Hence, we present here a kind of super blinking and biocompatible nanoprobes (denoted as SBNs) for SMLM. The SBNs have two main advantages, first, they possess an outstanding fluorescence blinking. Second, they are biocompatible since they are based on bovine serum albumin (BSA). The SBNs are fabricated by doping organic dyes into BSA nanoparticles. We fabricated two kinds of SBNs, one was doped with Alexa Fluor 647 (A647) and the other was doped with Alexa Fluor 594 (A594). Especially for A594 doped SBNs, the improved blinking of A594 doped SBNs induced a better localization precision as compared with A594 alone. Moreover, SMLM imaging of breast cancer cells and exosomes using the SBNs was successfully realized with high spatial resolutions. The work demonstrated here provides a new strategy to prepare novel kinds of super blinking fluorescent agents for SMLM, which broadens the selection of suitable fluorophores for SMLM.

2,2'-(1,2-Ethanediyldithio)bis(1,3-benzothiazole).

In the title compound, C(16)H(12)N(2)S(4), which is the result of the S-alkylation reaction of 2-mercaptobenzothiazole with ethylene dibromide, the planes of the two benzothiazole moieties form a dihedral angle of 3.84 (14) degrees. The bridging chain moiety, -SCH(2)CH(2)S-, adopts an antiperiplanar conformation. There are intermolecular S.S non-bonded contacts of 3.6471 (9) A, which stabilize the crystal packing.