Resorcinol-formaldehyde resin-based porous carbon spheres with high CO_2 capture capacities

Porous carbon spheres are prepared by direct carbonization of potassium salt of resorcinol-formaldehyde resin spheres, and are investigated as COadsorbents. It is found that the prepared carbon materials still maintain the typical spherical shapes after the activation, and have highly developed ultra-microporosity with uniform pore size, indicating that almost the activation takes place in the interior of the polymer spheres. The narrow-distributed ultra-micropores are attributed to the "in-situ homogeneous activation"effect produced by the mono-dispersed potassium ions as a form of -OK groups in the bulk of polymer spheres. The CS-1 sample prepared under a KOH/resins weight ratio of 1 shows a very high COcapture capacity of 4.83 mmol/g and good CO/Nselectivity of7-45. We believe that the presence of a welldeveloped ultra-microporosity is responsible for excellent COsorption performance at room temperature and ambient pressure.

Visual tracking based on transfer learning of deep salience information

In this paper,we propose a new visual tracking method in light of salience information and deep learning.Salience detection is used to exploit features with salient information of the image.Complicated representations of image features can be gained by the function of every layer in convolution neural network(CNN).The characteristic of biology vision in attention-based salience is similar to the neuroscience features of convolution neural network.This motivates us to improve the representation ability of CNN with functions of salience detection.We adopt the fully-convolution networks(FCNs)to perform salience detection.We take parts of the network structure to perform salience extraction,which promotes the classification ability of the model.The network we propose shows great performance in tracking with the salient information.Compared with other excellent algorithms,our algorithm can track the target better in the open tracking datasets.We realize the 0.5592 accuracy on visual object tracking 2015(VOT15)dataset.For unmanned aerial vehicle 123(UAV123)dataset,the precision and success rate of our tracker is 0.710 and 0.429.

Stick-slip nonuniform rotation distortion correction in distal scanning optical coherence tomography catheters

We present a robust and fiducial-marker-free algorithm that can identify and correct stick-slip distortion caused by nonuniform rotation(or beam scanning)in distally scanned catheters for endoscopic optical coherence tomography(OCT)images.This algorithm employs spatial fre-quency analysis to select and remove distortions.We demonstrate the feasibility of this algorithm on images acquired from ex vivo rat colon with a distally scanned DC motor-based endoscope.The proposed algorithm can be applied to general endoscopic OCT images for correcting non-uniform rotation distortion.

EXACT SOLUTIONS FOR THE CAUCHY PROBLEM TO THE 3D SPHERICALLY SYMMETRIC INCOMPRESSIBLE NAVIER-STOKES EQUATIONS

In this article, we establish exact solutions to the Cauchy problem for the 3 D spherically symmetric incompressible Navier-Stokes equations and further study the existence and asymptotic behavior of solution.

Erratum to:Black phosphorus quantum dots as multifunctional nanozymes for tumor photothermal/catalytic synergistic therapy

Erratum to Nano Research 2022,15(2):1554–1563 https://doi.org/10.1007/s12274-021-3701-8 Figure 3(d)in the original paper contained duplicated micrographs(BPQDs+NIR)for different xenografts(B16 vs.CNE-2).This error did not affect any of the conclusions from the published paper.

Biochemistry of mammalian ferritins in the regulation of cellular iron homeostasis and oxidative responses

Ferritin,an iron-storage protein,regulates cellular iron metabolism and oxidative stress.The ferritin structure is characterized as a spherical cage,inside which large amounts of iron are deposited in a safe,compact and bioavailable form.All ferritins readily catalyze Fe(II)oxidation by peroxides at the ferroxidase center to prevent free Fe(II)from participating in oxygen free radical formation via Fenton chemistry.Thus,ferritin is generally recognized as a cytoprotective stratagem against intracellular oxidative damage.The expression of cytosolic ferritins is usually regulated by iron status and oxidative stress at both the transcriptional and post-transcriptional levels.The mechanism of ferritin-mediated iron recycling is far from clarified,though nuclear receptor co-activator 4(NCOA4)was recently identified as a cargo receptor for ferritin-based lysosomal degradation.Cytosolic ferritins are heteropolymers assembled by H-and L-chains in different proportions.The mitochondrial ferritins are homopolymers and distributed in restricted tissues.They play protective roles in mitochondria where heme-and Fe/S-enzymes are synthesized and high levels of ROS are produced.Genetic ferritin disorders are mainly related to the L-chain mutations,which generally cause severe movement diseases.This review is focused on the biochemistry and function of mammalian intracellular ferritin as the major iron-storage and anti-oxidation protein.

An extract from the earthworm Eisenia fetida non-specifically inhibits the activity of influenza and adenoviruses

OBJECTIVE： To test the in vitro antiviral activity of a crude tissue extract （CTE/from the earthworm Eisenia fetida, determine any effective components in the CTE, andelucidate possiblemechanismsofaction. METHODS： A CTE was made by homogenizing earthworms, followed by treatment with ammoni- um sulfate, then thermal denaturation. Inhibition of virus-induced cytopathic effect （CPE） was used to assess antiviral activity. Chromatographic analy- sis was used to identify effective components in the CTE. RESULTS： The CTE inhibited viral CPE at non-cyto- toxic concentrations. Chromatography indicated that antiviral components corresponded to three active peaks indicative of proteases, nucleases and lysozymes. For adenoviruses, reduction in viral ac- tivity occurred for 100 lag/mL CTE. The reduction in adenoviral activity for four fractions was 100%, 91.8%, 86.9%, and 94.7%. For influenza viruses, re- duction in viral activity of 100%, 86.6%, 69.1% and 88.3% was observed for 37 pg/mL CTE. In addition, three active fractions mixture had stronger antiviral activity （98.7% and 96.7%） than three fractions alone.Gel electrophoresis results indicated that nu- cleases from E. fetida could degrade the genome of influenza viruses and adenoviruses. CONCLUSION： The earthworm CTE displayed non-specific antiviral properties, possibly mediated by a combination of proteases, nucleases and lyso- zymes. Nucleases likely participate in the antiviral process, and degrade the genome of the virus thereby preventing further replication.

Black phosphorus quantum dots as multifunctional nanozymes for tumor photothermal/catalytic synergistic therapy

Nanozymes are nanomaterials with enzyme-like properties that have attracted significant interest owing to their high stability,easy preparation,and tunable catalytic properties,especially in the field of cancer therapy.However,the unfavorable catalytic effects of nanozymes in the acidic tumor microenvironment have limited their applications.Herein,we developed a biomimetic erythrocyte membrane-camouflaged ultrasmall black phosphorus quantum dots(BPQDs)nanozymes that simultaneously exhibited an exceptional near-infrared(NIR)photothermal property and dramatically photothermal-enhanced glucose oxidase(GOx)-like activity in the acidic tumor microenvironment.We demonstrated the engineered BPQDs gave a photothermal conversion efficiency of 28.9%that could rapidly heat the tumor up to 50℃ while effectively localized into tumors via homing peptide iRGD leading after intravenously injection.Meanwhile,the significantly enhanced GOx-like activity of BPQDs under NIR irradiation was capable of catalytical generating massive toxic reactive oxygen species via using cellular glucose.By combining the intrinsic photothermal property and the unique photothermal-enhanced GOx-like catalytic activity,the developed BPQDs were demonstrated to be an effective therapeutic strategy for inhibiting tumor growth in vivo.We believe that this work will provide a novel perspective for the development of nanozymes in tumor catalytic therapy.

Photodegradation of 2,4-D induced by NO_2^- in aqueous solutions: The role of NO_2

To elucidate the effect of nitrite ion （NO2^-） on the photodegradation of organic pollutants, a 300 W mercury lamp and Pyrex tubes restricting the transmission of wavelengths below 290nm were used to simulate sunlight, and the photodegradation processes of 2,4-dichlorophenoxyacetic acid （2,4-D） with different concentrations of NO2^- in freshwater and seawater were studied. The effect of reactive oxygen species （ROS） on the photolysis of 2,4-D was also demonstrated using electron paramagnetic resonance （EPR）. The results indicated that the 2,4-D photolysis reaction followed the first-order kinetics in freshwater and seawater under different concentrations of NO2^-. Meanwhile, the photochemical reaction rate of 2,4-D increased with increasing concentration of NO2^-. When the concentration of NO2^- was lower than 23 mg/L, the photodegradation rate of 2,4-D in seawater was higher than that in freshwater. However, when the concentration of NO2^- was reached 230 mg/L, 2,4-D degradation slowed down in seawater. It was important to note that EPR spectra showed NO2 radical was generated in the NO5 solution under simulated sunlight irradiation, indicating that 2,4-D photodegradation could be induced by NO2. These results show the key role of NO2^- in photochemistry and are helpful for better understanding of the phototransformation of environmental contaminants in natural aquatic systems.

A natural nanozyme in life is found:the iron core within ferritin shows superoxide dismutase catalytic activity

Nanozymes are nanomaterials exhibiting intrinsic enzymatic properties,which suggests that inorganic nanoparticles could be bioactive.It’s in 2007,when we introduced the biological methodologies for natural enzymes to systematically study the enzymatic properties of iron oxide nanoparticles,we discovered nanozymes.We found that nanozymes,just as natural enzymes,are able to catalyze biochemical reactions under the physiological conditions,following the similar enzymatic kinetics and catalytic mechanisms(Gao et al.,2007).Since then,the developments of nanozymes bloomed,and lots of nanomaterials were found exhibiting various enzymatic activities(Huang et ah,2019).