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Biomass-derived porous carbons are one kind of sustainable, extensive, and flexible carbon material for CO2 capture. Here, we prepared several microporous carbons from poplar wood by three preparation routes. Especially, the residues of the poplar wood after the bioethanol process were explored as precursors to prepare activated carbon by KOH and ZnCl2 activation. By the adjustment of the preparation routes and the optimization of the activation conditions, these porous carbons exhibited diversified morphology (sponge, nanosheets, and honeycomb structure), tunable porosity (specific surface areas: 511-2153 m2/g), and narrow micropore distribution (0.55-1.2 nm). These carbons had a high CO2 uptake of up to 217 mg/g at 273 K and 1 bar, which was comparable with those of many N-doped porous carbons, and possessed moderate isosteric heat of CO2 adsorption (21.1-43.2 kJ/mol), good cyclic ability, and high CO2/N2 selectivity (Henry's law: 44.0). The results indicated that CO2 uptake of these carbons was mainly decided by their micropore volume (d < 1.0 nm) at 273 K and 1 bar. This work provides an important reference for preparing promising CO2 adsorbents with tunable structures from similar biomass resources.

Through coarse-grained molecular-dynamic simulation of polymer-grafted nanoparticles in a lamellar forming diblock copolymer (BCP), we systematically study the effects of the grafting density (Ng), the compatibility between the grafted chains and the A-block of BCPs (εgA), and the NPs number (N) on the distance (D) of the NPs from the interface by proposing a novel characterization parameters of the orientation and distribution of the grafted chains. The nanoparticle gradually migrates away from the interface and into the A-block region with the increase of εgA for all studied Ng, while slightly returns towards the interface at high εgA and great Ng, which is the first observation of non-monotonic migration at the molecular level. We ascribe the reason of this to the behavior of the grafted chains that are near the interface. Furthermore, we classify the grafted chains into three types along the normal direction of the interface and the migration process is illustrated by the distribution and orientation of the different types of grafted chains, together with the radial distribution function between the NP and the A-block chains. We observe the formation of the NPs layers parallel to the interface for N

What are the risks associated with cryopreserved semen collected during and after the coronavirus disease 2019 (COVID-19) pandemic wave in Wuhan, China?Retrospective cohort study involving young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank (China) during the pandemic wave (1 January 2020 to 30 January 2020) and after the wave and return to work (7 April 2020 to 30 May 30 2020). One hundred paired semen and blood specimens from 100 donors were included. One-step single-tube nested quantitative real-time polymerase chain reaction (OSN-qRT-PCR) was used to detect SARS-CoV-2. Moreover, to control the unacceptable risk of false-negative results, a second round of screening was performed with pooled RNA from negative semen samples using crystal digital PCR (cd-PCR).For individual blood and semen samples, the target genes, namely the nucleocapsid protein (N) and open reading frame (ORF-1ab) genes, tested negative in all of the 100 paired samples. Further, as per cd-PCR results, there were20,000 droplets per well in the RNA for each combined sample and no positive droplets were present for either of the aforementioned target genes. A total of 100 paired semen and blood samples from these two groups tested negative for SARS-CoV-2.Cryopreserved semen at the Hunan Province Human Sperm Bank during and after the COVID-19 pandemic wave was free of SARS-CoV-2 and was judged safe for external use in the future.

Formaldehyde (FA), as a reactive carbonyl species and signaling molecule, plays an important role in living systems. Here, an FA-responsive probe with fast response and great selectivity is designed based on aggregation-induced emission. The probe is prepared by functionalizing tetraphenylethene (TPE) with two amine groups. FA is detected based on the solubility differences between the amine-functionalized TPE and the corresponding Schiff bases after reaction with FA. The probe exhibits a limit of detection of 40 nM and a response time of ∼90 s. Furthermore, its ability to detect both endogenous and exogenous FA is demonstrated in living cells with high specificity. Moreover, the probe is also introduced to image endogenous FA in real time with fast response. These results suggest that our probe holds great potential for tracking FA in living systems under various physiological conditions as well as related biomedical applications.

An efficient, catalyst-free strategy to construct diarylmethyl sulfones via 1,6-conjugate addition/aromatization/sulfonylation reaction of para-quinone methides with sulfonyl hydrazides under mild and environmentally benign conditions has been developed. The established protocol provided a highly chemo- and regioselectivity synthesis of a diverse array of novel diarylmethyl sulfones with excellent yields, and the reaction could be scaled up.

In this paper we adopt molecular-dynamics simulations to study the amphiphilic AB block-copolymer (BCP) mediated nanoparticles (NPs) dispersion in polymer nanocomposites (PNCs), with the A-block being compatible with the NPs and the B-block being miscible with the polymer matrix. The effects of the number and components of BCP, as well as the interaction strength between A-block and NPs on the spatial organization of NPs are explored. We find the increase of the fraction of the A-block brings different dispersion effect to NPs than that of B-block. We also find that the best dispersion state of the NPs occurs in the case of a moderate interaction strength between the A-block and the NPs. Meanwhile, the stress-strain behaviour is probed. Our simulation results verify that adopting BCP is an effective way to adjust the dispersion of NPs in the polymer matrix, further to manipulate the mechanical properties.