The COVID‐19 pandemic caused by SARS‐CoV‐2 is threating global health. Inhibiting interaction of the receptor‐binding domain of SARS‐CoV‐2 S protein (SRBD) and human ACE2 receptor is a promising ...treatment strategy. However, SARS‐CoV‐2 neutralizing antibodies are compromised by their risk of antibody‐dependent enhancement (ADE) and unfavorably large size for intranasal delivery. To avoid these limitations, we demonstrated an aptamer blocking strategy by engineering aptamers’ binding to the region on SRBD that directly mediates ACE2 receptor engagement, leading to block SARS‐CoV‐2 infection. With aptamer selection against SRBD and molecular docking, aptamer CoV2‐6 was identified and applied to prevent, compete with, and substitute ACE2 from binding to SRBD. CoV2‐6 was further shortened and engineered as a circular bivalent aptamer CoV2‐6C3 (cb‐CoV2‐6C3) to improve the stability, affinity, and inhibition efficacy. cb‐CoV2‐6C3 is stable in serum for more than 12 h and can be stored at room temperature for more than 14 days. Furthermore, cb‐CoV2‐6C3 binds to SRBD with high affinity (Kd=0.13 nM) and blocks authentic SARS‐CoV‐2 virus with an IC50 of 0.42 nM.
We propose an aptamer blocking strategy to inhibit SARS‐CoV‐2 infection. With the advantages of small size, rapid kinetics, high stability, sophisticated programmability and high security, our aptamers have great potential as prophylactic and therapeutic agents, which could greatly assist in the intervention of prevailing and emerging infectious diseases other than COVID‐19.
Non-small cell lung cancer (NSCLC) is the major cause of cancer-associated death worldwide, but its underlying mechanisms remain to be fully elucidated. Long noncoding RNAs (lncRNAs) are known to ...play an important role in the aberrant regulation of gene expression in many cancers, including NSCLC. Here, we investigated the involvement of the lncRNA KTN1-AS1 in NSCLC. We found that KTN1-AS1 expression was upregulated in NSCLC tissue and was positively associated with poor prognosis. KTN1-AS1 knockdown inhibited cell growth and proliferation, increased apoptosis, and modulated the expression of cell cycle- and apoptosis-related proteins (cyclin A1, cyclin-dependent kinase 2, Bcl2, and Bax) in NSCLC cell lines and tumour xenografts in nude mice. KTN1-AS1 bound to and directly regulated the expression of miR-130a-5p. Notably, miR-130a-5p overexpression suppressed NSCLC cell proliferation and increased apoptosis in vitro and in vivo, and this effect was reversed by KTN1-AS1 overexpression. Finally, we showed that KTN1-AS1 modulated the expression of 3-phosphoinositide-dependent protein kinase 1 (PDPK1), a miR-130a-5p target and key regulator of autophagy in NSCLC cells. Taken together, our results suggest that the KTN1-AS1/miR-130a-5p/PDPK1 pathway may be a potential therapeutic target for NSCLC.
This paper focuses on the problem of fixed-time chaos suppression and stabilization of a class of Lorenz systems with uncertain parameters. Based on the fixed-time stability theory, adaptive control ...and backstepping algorithm, a novel adaptive practical fixed-time controller is proposed. It is shown that the presented control scheme can guarantee that all the signals of the closed-loop system are bounded and chaotic phenomenon is suppressed in the fixed time. Both the theoretical analysis and simulation results verify the effectiveness of the proposed control strategy.
This paper presents an in-depth comparative study of the effects of different molten salt systems, catalyst additions, preparation temperatures, temperature rise rates, and holding times on the ...properties of mullite whiskers during their preparation process, as well as exploring the enhancement of the toughening effect of mullite whiskers on ceramics. The morphology, crystal structure, and composition of the whiskers were analyzed via SEM, XRD, TG, strength tests, etc. The results show that the best-performing mullite whisker was prepared with an aluminum sulfate molten salt system, with the addition of aluminum fluoride catalyst at 4%, a temperature increase rate of 5 °C, a temperature increase up to 850 °C, and a holding time of 5 h, and its aspect ratio reached 20.64. By adding different contents of mullite whiskers and comparing the toughness strengths and wear rates of the silicon carbide ceramics, it was found that the toughness strength of the ceramics was improved by more than 16.5% and the wear rate was lower than 0.4% when the addition of mullite whisker was more than 3%.
Human papillomavirus (HPV), the most common sexually transmitted disease, is involved in a series of other diseases. The persistent infection of high-risk HPVs (HR-HPVs) is considered to be the ...causative agent of cervical cancer, and it is related to noncervical cancers. The present study aims to estimate the HPV prevalence and genotype distribution in Jilin province, China, to guide HPV-related cervical cancer screening and HPV vaccination.
From October 2017 to September 2019, 21,282 samples (634 male and 20,648 female) were collected for HPV infection detection using an HPV genotyping panel. The age-related HPV prevalence and morbidity of HPV-based disease and HPV prevalence associated with specific diseases were analyzed.
A total of 7095 (34.4%) positive for HPV infection of 20648 women, and 164 (25.8%) positive of 634 men. The HPV prevalence among women exhibited a bimodal pattern, with a peak in young group and a second peak in old group, with increased severity of cervical lesions. HPV16 (7.8%), HPV52 (5.8%), HPV58 (5.0%), HPV53 (3.4%), and HPV51 (3.0%) were the most prevalent genotypes among women, and HPV6 (6.0%), HPV11 (5.7%), HPV16 (3.6%), HPV18 (2.7%), and HPV51 (3.0%) were prevalent among men. Non-vaccine-covered HPV53 and 51 were found in 6.3% of HPV infection and 8.9% of cervical cancer in Jilin province. Furthermore, 45.5% of females and 28.6% of males with genital warts were infected with HR-HPV genotypes.
The HPV genotypic spectrum in Jilin province, where non-vaccine-covered HPV53 and 51 were prevalent, exhibited an age- and cervical lesion-specific pattern, which provides guidance for HPV vaccination and cervical cancer screening. HPV infection in men and benign hyper-proliferative lesions should not be neglected.
Chemical reactions between Be+ ions and H2 molecules have significance in the fields of ultracold chemistry and astrophysics, but the corresponding dynamics studies on the ground-state reaction have ...not been reported because of the lack of a global potential energy surface (PES). Herein, a globally accurate ground-state BeH2+ PES is constructed using the neural network model based on 18,657 ab initio points calculated by the multi-reference configuration interaction method with the aug-cc-PVQZ basis set. On the newly constructed PES, the state-to-state quantum dynamics calculations of the Be+(2S) + H2(v0 = 0; j0 = 0) and Be+(2S) + D2(v0 = 0; j0 = 0) reactions are performed using the time-dependent wave packet method. The calculated results suggest that the two reactions are dominated by the complex-forming mechanism and the direct abstraction process at relatively low and high collision energies, respectively, and the isotope substitution has little effect on the reaction dynamics characteristics. The new PES can be used to further study the reaction dynamics of the BeH2+ system, such as the effects of rovibrational excitations and alignment of reactant molecules, and the present dynamics data could provide an important reference for further experimental studies at a finer level.
This work proposes an efficient catalytic recovery and utilization method for waste polyurethane foam. This method uses ethylene glycol (EG) and propylene glycol (PPG) as two-component alcohololytic ...agents for the alcoholysis of waste polyurethane foams. For the preparation of recycled polyethers, the conditions of different catalytic degradation systems were catalyzed by duplex metal catalysts (DMC) and alkali metal catalysts, and a synergy with both was also used. The experimental method was adopted with the blank control group and was set up for comparative analysis. The effect of the catalysts on the recycling of waste polyurethane foam was investigated. The catalytic degradation of DMC and the alkali metal catalysts alone, as well as the synergistic effect of the two catalysts, was explored. The findings revealed that the NaOH and DMC synergistic catalytic system was the best, and that the system activity was high under a two-component catalyst synergistic degradation. When the amount of NaOH added in the degradation system was 0.25%, the amount of DMC added was 0.04%, the reaction time was 2.5 h, and the reaction temperature was 160 °C, the waste polyurethane foam was completely alcoholized, and the prepared regenerated polyurethane foam had high compressive strength and good thermal stability. The efficient catalytic recycling method of waste polyurethane foam proposed in this paper has certain guiding and reference values for the practical production of solid-waste-recycled polyurethane.
Even after being abandoned for many years, a large number of weathered crust elution-deposited rare earth (WCED-RE) tailings continue to release ammonia nitrogen (AN) pollution into their surrounding ...environments. However, the influences of particle size distribution and clay minerals on AN pollution caused by these tailings have been insufficiently studied, and its causes are poorly understood. In this study, soil samples at different depths (5, 7, 9, 11 and 14 m) were collected from a rare earth tailing in Ganzhou City, Jiangxi Province, China. Particles were screened by size into six groups (2–1, 1–0.5, 0.5–0.25, 0.25–0.1, 0.1–0.075 and < 0.075 mm), and AN forms were extracted. The results showed that as soil particle size decreases, both soil specific surface area and clay content increase, leading to stronger AN enrichment ability. With increased sampling depth, the distribution of clay across the six particle fractions became more uniform, such that the accumulation of AN in soil with fine particle size was less obvious. Clay minerals with different capacities for AN enrichment vary with sampling depth. This variation is responsible for the profile of AN distribution in the mine, where AN first increases and then decreases as vertical depth is increased. Although AN content was highest at 11 m, water soluble AN content was higher in the upper part of the completely weathered layer (5 and 7 m), which poses a higher environmental risk. This study provides significant information to deepen our understanding of the distribution characteristics of AN and its main influencing factors, as well as a foundation for the prevention and remediation of nitrogen pollution from WCED-RE tailings.
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•Levels of ammonium nitrogen (AN) increase as particle size decreases.•AN distributes more evenly across various particle fractions with increasing depth.•As depth increases, variation in clay minerals causes AN to increase, then decrease.
Modern plant breeding relies heavily on the deployment of susceptibility and resistance genes to defend crops against diseases. The expression of these genes is usually regulated by transcription ...factors including members of the AP2/ERF family. While these factors are a vital component of the plant immune response, little is known of their specific roles in defense against
f. sp.
tropical race 4 (
TR4) in banana plants. In this study, we discovered that MaERF12, a pathogen-induced ERF in bananas, acts as a resistance gene against
TR4. The yeast two-hybrid assays and protein-protein docking analyses verified the interaction between this gene and MaSMG7, which plays a role in nonsense-mediated RNA decay. The transient expression of MaERF12 in
was found to induce strong cell death, which could be inhibited by MaSMG7 during co-expression. Furthermore, the immunoblot analyses have revealed the potential degradation of MaERF12 by MaSMG7 through the 26S proteasome pathway. These findings demonstrate that MaSMG7 acts as a susceptibility factor and interferes with MaERF12 to facilitate
TR4 infection in banana plants. Our study provides novel insights into the biological functions of the MaERF12 as a resistance gene and MaSMG7 as a susceptibility gene in banana plants. Furthermore, the first discovery of interactions between MaERF12 and MaSMG7 could facilitate future research on disease resistance or susceptibility genes for the genetic improvement of bananas.
High temperatures significantly affect the growth, development, and yield of plants. Anoectochilus roxburghii prefers a cool and humid environment, intolerant of high temperatures. It is necessary to ...enhance the heat tolerance of A. roxburghii and breed heat-tolerant varieties. Therefore, we studied the physiological indexes and transcriptome of A. roxburghii under different times of high-temperature stress treatments. Under high-temperature stress, proline (Pro), H.sub.2O.sub.2 content increased, then decreased, then increased again, catalase (CAT) activity increased continuously, peroxidase (POD) activity decreased rapidly, then increased, then decreased again, superoxide dismutase (SOD) activity, malondialdehyde (MDA), and soluble sugars (SS) content all decreased, then increased, and chlorophyll and soluble proteins (SP) content increased, then decreased. Transcriptomic investigation indicated that a total of 2740 DEGs were identified and numerous DEGs were notably enriched for "Plant-pathogen interaction" and "Plant hormone signal transduction". We identified a total of 32 genes in these two pathways that may be the key genes for resistance to high-temperature stress in A. roxburghii. To sum up, the results of this study provide a reference for the molecular regulation of A. roxburghii's tolerance to high temperatures, which is useful for further cultivation of high-temperature-tolerant A. roxburghii varieties.
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