Potential role of quorum quenching activity of silver nanoparticles in controlling non-filamentous bulking within activated sludge process.

The effective prevention and control of non-filamentous bulking is a significant challenge. In this study, the underlying effect of quorum sensing (QS) on inducing non-filamentous bulking and the maintenance effect of silver nanoparticles (AgNPs) on sludge floc stability, aggregation and settleability based on the quorum quenching (QQ) activity during non-filamentous bulking were investigated. The results showed that the concentration of N-acyl homoserine lactone (AHL) increased significantly in the activated sludge system at a high organic load rate (OLR), triggering the AHL-mediated QS. Additionally, the triggered QS promoted exopolysaccharide secretion, reducing the surface charge and hydrophobicity of the sludge aggregates, and further deteriorating the settleability of the sludge aggregates. AgNPs, a quorum sensing inhibitor (QSI), inhibited the AHL-QS based on QQ activity under high OLR, which maintained the physicochemical properties of extracellular polymeric substances (EPS). AgNPs-QQ maintained the surface energy barrier and electrostatic barrier of sludge aggregates and the gel properties of exopolysaccharides, which is favorable for microbial aggregation. The appropriate concentrations of AgNPs (≤10 mg/L) had no negative effect on biological nutrient removal in the sequencing batch reactors (SBRs) at the high organic loading. Therefore, AgNPs effectively prevent and control non-filamentous bulking by their QQ activity in the activated sludge process. Thus, the present study provided new insights into controlling non-filamentous bulking during the activated sludge process.

Reactive Blending of Recycled Poly(ethylene terephthalate)/Recycled Polypropylene: Kinetics Modeling of Non-Isothermal Crystallization.

Plastics were developed to change our world for the better. However, plastic pollution has become a serious global environmental crisis. Thermoplastic polyesters and polyolefins are among the most abundant plastic waste. This work presents an in-depth non-isothermal crystallization kinetics analysis of recycled post-consumer poly(ethylene terephthalate) (rPET) and recycled polypropylene (rPP) blends prepared through reactive compounding. The effect of pyromellitic dianhydride (PMDA) on crystallization kinetics and phase morphology of rPET/rPP blends was investigated by differential scanning calorimetry (DSC) and microscopy techniques. DSC results showed that increasing rPP content accelerated rPET crystallization while reducing crystallinity, which indicates the nucleation effect of the rPP phase in blends. Further, it was found that the incorporation of PMDA increased the degree of crystallinity during non-isothermal crystallization, even though the rate of crystallinity decreased slightly due to its restriction effects. The non-isothermal crystallization kinetics was analyzed based on the theoretical models developed by Jeziorny, Ozawa, Mo, and Tobin. The activation energy of the crystallization process derived from Kissinger, Takhor, and Augis-Bennett models was found to increase in rPET/rPP blends with increasing PMDA due to hindered dynamics of the system. Rheological measurements revealed that rPET melt viscosity is remarkably increased in the presence of PMDA and reactive blending with rPP relevant for processing. Moreover, nanomechanical mapping of the rPP phase dispersed in the rPET matrix demonstrated the broadening of the interfacial domains after reactive blending due to the branching effect of PMDA. Findings from this study are essential for the recycling/upcycling thermoplastics through non-isothermal fabrication processes, such as extrusion and injection molding, to mitigate the lack of sorting options.

Silver nanoparticles induced with aqueous black carpenter ant extract selectively inhibit the growth of Pseudomonas aeruginosa.

Aqueous black carpenter ant extract (ABCAE) was used to synthesize silver nanoparticles (AgNPs). The ABCAE was rich in water-soluble compounds such as hydrophilic polypeptides that behaved as both reducing and stabilizing agents for generating AgNPs from Ag+ ion precursors. The diameter of the observed AgNPs was mostly in the range of 20-60 nm. The AgNPs were tested as an antibacterial agent for the growth inhibition of two pathogenic bacteria (Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 27661) and one common bacteria (Escherichia coli K12 ATCC 10798). Disk diffusion test showed that the AgNPs selectively inhibited the growth of P. aeruginosa but not for the other two species, suggesting the potential application of the green-chemically synthesized AgNPs as a selective antibacterial agent without harming other beneficial bacteria.

Synthesis and Characterization of Quercetin-Iron Complex Nanoparticles for Overcoming Drug Resistance.

Quercetin, one of the major natural flavonoids, has demonstrated great pharmacological potential as an antioxidant and in overcoming drug resistance. However, its low aqueous solubility and poor stability limit its potential applications. Previous studies suggest that the formation of quercetin-metal complexes could increase quercetin stability and biological activity. In this paper, we systematically investigated the formation of quercetin-iron complex nanoparticles by varying the ligand-to-metal ratios with the goal of increasing the aqueous solubility and stability of quercetin. It was found that quercetin-iron complex nanoparticles could be reproducibly synthesized with several ligand-to-iron ratios at room temperature. The UV-Vis spectra of the nanoparticles indicated that nanoparticle formation greatly increased the stability and solubility of quercetin. Compared to free quercetin, the quercetin-iron complex nanoparticles exhibited enhanced antioxidant activities and elongated effects. Our preliminary cellular evaluation suggests that these nanoparticles had minimal cytotoxicity and could effectively block the efflux pump of cells, indicating their potential for cancer treatment.

Mechanisms of survival mediated by the stringent response in Pseudomonas aeruginosa under environmental stress in drinking water systems: Nitrogen deficiency and bacterial competition.

Pseudomonas aeruginosa causes public health problems in drinking water systems. This study investigated the potential role of the stringent response in regulating the adaptive physiological metabolic behaviors of P. aeruginosa to low nitrogen stress and bacterial competition in drinking water systems. The results indicated that guanosine tetraphosphate (ppGpp) concentrations in P. aeruginosa increased to 135.5 pmol/g SS under short-term nitrogen deficiency. Meanwhile, the expression levels of the ppGpp synthesis genes (ppx, relA) and degradation gene (spoT) were upregulated by 37.0% and downregulated by 26.8%, respectively, indicating that the stringent response was triggered. The triggered stringent response inhibited the growth of P. aeruginosa and enhanced the metabolic activity of P. aeruginosa to adapt to nutrient deprivation. The interspecific competition significantly affected the regulation of the stringent response in P. aeruginosa. During short-term nitrogen deficiency, the extracellular polymeric substances concentration of P. aeruginosa decreased significantly, leading to desorption and diffusion of attached bacteria and increased ecological risks. The regulatory effect of stringent response on P. aeruginosa gradually weakened under long-term nitrogen deficiency. However, the expression of pathogenic genes (nalD/PA3310) and flagellar assembly genes (fliC) in P. aeruginosa was upregulated by the stringent response, which increased the risk of disease.

The Invasive Species Reynoutria japonica Houtt. as a Promising Natural Agent for Cardiovascular and Digestive System Illness.

Polygoni Cuspidati Rhizoma et Radix, the dry roots and stems of Reynoutria japonica Houtt (called Huzhang, HZ in Chinese), is a traditional and popular chinese medicinal herb for thousands of years. As a widely used ethnomedicine in Asia including China, Japan, and Korea, HZ can invigorate the blood, cool heat, and resolve toxicity, which is commonly used in the treatment of favus, jaundice, scald, and constipation. However, HZ is now considered an invasive plant in the United States and many European countries. Therefore, in order to take advantage of HZ and solve the problem of biological invasion, scholars around the world have carried out abundant research studies on HZ. Until now, about 110 compounds have been isolated and identified from HZ, in which anthraquinones, stilbenes, and flavonoids would be the main bioactive ingredients for its pharmacological properties, such as microcirculation improvement, myocardial protective effects, endocrine regulation, anti-atherosclerotic activity, anti-oxidant activity, anti-tumor activity, anti-viral activity, and treatment of skin inflammation, burns, and scalds. HZ has a variety of active ingredients and broad pharmacological activities. It is widely used in health products, cosmetics, and even animal husbandry feed and has no obvious toxicity. Efforts should be made to develop more products such as effective drugs, health care products, cosmetics, and agricultural and animal husbandry products to benefit mankind.

A high-calorie diet aggravates LPS-induced pneumonia by disturbing the gut microbiota and Th17/Treg balance.

The intestinal flora plays an important role in the inflammatory response to the systemic or local infections in the host. A high-calorie diet has been shown to aggravate pneumonia and delay recovery, especially in children. However, the underlying mechanisms remain unclear. Our previous studies demonstrated that a high-calorie diet and LPS atomization synergistically promoted lung inflammation injury in juvenile rats. In this study, specific pathogen-free juvenile rats were placed in a routine environment, and subjected to a high-calorie diet or LPS atomization in isolation as well as combination. Our data revealed that LPS nebulization combined with a high-calorie diet resulted in significant changes in rats, such as slow weight gain, increased lung index, and aggravated lung inflammatory damage. Meanwhile, we found that the aggravation of LPS-induced pneumonia by a high-calorie diet disturbs the balance of Th17/Treg cells. Furthermore, high-throughput sequencing of intestinal contents revealed that a high-calorie diet changed the gut microbiome composition, decreased microbial diversity, and particularly reduced the abundance of the intestinal microbiota associated with the production of short-chain fatty acids (SCFAs) in rats. Consequently, the levels of SCFAs, especially acetate, propionate, and butyrate, were significantly decreased following the intervention of a high-calorie diet. More critically, the effects of a high-calorie diet were shown to be transmissible among pneumonia rats through cohousing microbiota transplantation. Taken together, we provide evidence to support that a high-calorie diet can potentially reset the gut microbiome and metabolites, disrupt Th17/Treg cell balance and immune homeostasis, and aggravate LPS-induced lung inflammatory damage, which may provide a new perspective on the pathogenesis of lung inflammation injury, and suggest a novel microbiota-targeting therapy for inflammatory lung diseases.

New insight into filamentous sludge bulking: Potential role of AHL-mediated quorum sensing in deteriorating sludge floc stability and structure.

The microcosmic mechanisms underlying filamentous bulking remain unclear. The role of extracellular polymeric substances (EPS) governed by quorum sensing (QS) in deteriorating sludge floc stability and structure during filamentous bulking and the feasibility of using quorum quenching (QQ) to maintain sludge floc stability and structure and sludge settling were investigated in this study. The results indicated that the concentration of C6HSL increased from 22.08±3.22 ng/g VSS to 81.42±5.98 ng/g VSS during filamentous bulking. The filamentous bacteria gradually evolved the hdtS gene related to the synthesis of C6HSL with increases in the population density. Triggered QS by filamentous bacteria proliferation induced variation in the composition and structure of EPS within the sludge flocs. The proteins (PN) content of the EPS increased evidently from 40.06 ± 2.41 mg/g VSS to 110.32 ± 4.32 mg/g VSS, and the polysaccharides (PS) content slightly increased during filamentous bulking. The upregulated proteins in the EPS led to a decrease in the relative hydrophobicity of the sludge and an increase in negative surface charge. The α-helix/(ß-sheet+random coil) ratio evidently increased from 0.76 to 0.99 during filamentous bulking, revealing that the proteins were tightly structured, which prevented the exposure of inner hydrophobic groups. The total energy of the interaction (WT) between bacteria increased during sludge bulking, which resulted in the weakening of sludge aggregation. Variation in the physicochemical properties of EPS induced by QS in the filamentous bacteria markedly restrained adhesion between the filamentous bacteria and floc-forming bacteria. The production of PN in the EPS and the expression of the hdtS gene were inhibited by vanillin, which served as a QS inhibitor. The WT between bacteria with 50 mg/L of vanillin basically did not change. Filamentous bulking was significantly inhibited by the addition of vanillin. Therefore, QQ is a potential strategy for the prevention and control of filamentous bulking. This study provides new information regarding the microcosmic mechanisms of filamentous bulking.

Research on Chemically Deuterated Cellulose Macroperformance and Fast Identification.

Chemically deuterated cellulose fiber was expected to provide novel applications due to its spectral, biological, and kinetic isotope effect. In this research, the performance of the chemically deuterated cotton fibers, including their mechanical property, enzymatic degradation performance, effect on bacterial treatment, and fast identification (near-infrared modeling) was investigated. The breaking tenacity of the deuterated cotton fibers was slightly lower, which might be attributed to the structural damage during the chemical deuteration. The glucose yield by enzymatic hydrolysis was less than that of the protonic cotton fibers, implying the deuterated fibers are less sensitive to enzymatic degradation. Furthermore, the deuterated fibers could promote the growth of bacteria such as Escherichia. coli, which was associated with the released low-level deuterium content. At last, the near-infrared technique combined with partial least squares regression successfully achieved a fast identification of the protiated and deuterated cotton fibers, which significantly promoted the potential application of deuterated cellulose as anticounterfeiting materials (e.g., special paper).

MicroRNA-140-5p represses chondrocyte pyroptosis and relieves cartilage injury in osteoarthritis by inhibiting cathepsin B/Nod-like receptor protein 3.

Osteoarthritis (OA) is a degenerative joint disease. Dysregulated microRNA (miRNA) expressions are implicated in OA progression. Consequently, the current study set out to investigate the mechanism of miR-140-5p in OA cartilage injury. Firstly, the murine and cell models of OA were established, and cartilage tissues of OA mice were observed using hematoxylin and eosin staining and safranin O staining. Chondrocyte pyroptosis was further assessed using immunohistochemical and Calcein-AM/PI staining. The levels of gasdermin-D (GSDMD)-N, cleaved caspase-1, interleukin (IL)-1ß, and IL-18 in cartilage tissues and cells were determined using Western blot and enzyme-linked immunosorbent assay kits. The targeting relationship between miR-140-5p and cathepsin B (CTSB) was verified using a dual-luciferase assay. Moreover, the binding of CTSB and Nod-like receptor protein 3 (NLRP3) was detected using co-immunoprecipitation assay. Lastly, the effects of NLRP3 activation and CTSB overexpression on chondrocyte pyroptosis were documented. It was found that OA induction aggravated cartilage tissue injury and enhanced chondrocyte pyroptosis. miR-140-5p was poorly-expressed in OA models, and miR-140-5p over-expression alleviated chondrocyte pyroptosis, as evidenced by decreased GSDMD-N, cleaved caspase-1, IL-1ß, and IL-18 levels. miR-140-5p targeted the CTSB gene, whereas CTSB further bound to NLRP3 and activated the NLRP3 inflammasome. Additionally, CTSB over-expression or NLRP3 activation reversed the inhibitory effect of miR-140-5p on chondrocyte pyroptosis. Collectively, our findings revealed that miR-140-5p repressed chondrocyte pyroptosis and alleviated OA cartilage injury via inhibition of the CTSB/NLRP3. This study may confer a theoretical basis for the treatment of OA cartilage injury.

[Q-marker prediction of Magnoliae Officinalis Cortex before and after "sweating"].

Magnoliae Officinalis Cortex, a common Chinese medicinal in clinic, should undergo "sweating" process in producing area according to Chinese Pharmacopoeia, which affects its genuineness and quality. In light of the concept and research mode of quality marker(Q-marker) for decoction pieces, the active components of Magnoliae Officinalis Cortex pieces which altered significantly before and after "sweating" were identified in this study. The main pharmacodynamic material basis was clarified by pharmacodynamic, pharmacokinetic and drug property research, followed by the prediction of Q-markers of Magnoliae Officinalis Cortex before and after "sweating", for better improving its quality standard.

Comparison of nanostructure and nanomechanical properties of cast and air sides of polyimide films from different manufacturers.

Polyimide films are widely applied in harsh environments because of their outstanding performance. High-quality polyimide films are often manufactured through a two-step process. The complicated procedure results in different properties on the two sides, i.e., the air side and cast side of the films, and the quality of products from different manufacturers varies notably. In the present work, polyimide films with two thicknesses (1 and 2 mm) from four manufacturers were investigated. Atomic force microscope and FT-IR spectrometer were employed to monitor morphology, roughness, nanomechanical properties, and corresponding relative imidization degree on the two sides of each film. Statistical tools were applied to analyze the data. T-test suggests that the two sides of the same film were significantly different in roughness, DMT modulus, and relative imidization degree (p < 0.05). The roughness on the air side was consistently smaller than that of the cast side. ANOVA was used to compare differences among the manufacturers. Manufacturer B provided the smoothest films with the highest DMT moduli and imidization degrees. A positive correlation was found between the DMT modulus and imidization degree (r = 0.7330). Nanostructure and nanomechanical properties could affect the quality of the film. Striped morphology and adhesion were found on the cast side of the 2-mm film from manufacturer D, which compromised the film tension in the direction perpendicular to the strips. Investigations of morphology and mechanical properties of polyimide film at the nanoscale would help us better characterize the film, assure its quality, and select suitable film and side for proper applications.

Biodegradable and Reusable Cellulose-Based Nanofiber Membrane Preparation for Mask Filter by Electrospinning.

Environmentally friendly face masks with high filtration efficiency are in urgent need to fight against the COVID-19 pandemic, as well as other airborne viruses, bacteria and particulate matters. In this study, coaxial electrospinning was employed to fabricate a lithium chloride enhanced cellulose acetate/thermoplastic polyurethanes (CA/TPU-LiCl) face mask nanofiber filtration membrane, which was biodegradable and reusable. The analysis results show that the CA/TPU-LiCl membrane had an excellent filtration performance: when the filtration efficiency reached 99.8%, the pressure drop was only 52 Pa. The membrane also had an outstanding reusability. The filtration performance maintained at 98.2% after 10 test cycles, and an alcohol immersion disinfection treatment showed no effect on its filtration performance. In summary, the CA/TPU-LiCl nanofiber membrane made in this work is a promising biodegradable and reusable filtration material with a wide range of potential applications, including high-performance face mask.

Deciphering the Pharmacological Mechanisms of Ma Xing Shi Gan Decoction against COVID-19 through Integrating Network Pharmacology and Experimental Exploration.

The outbreak of new infectious pneumonia caused by SARS-CoV-2 has posed a significant threat to public health, but specific medicines and vaccines are still being developed. Traditional Chinese medicine (TCM) has thousands of years of experience in facing the epidemic disease, such as influenza and viral pneumonia. In this study, we revealed the efficacy and pharmacological mechanism of Ma Xing Shi Gan (MXSG) Decoction against COVID-19. First, we used liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) to analyze the chemical components in MXSG and identified a total of 97 components from MXSG. Then, the intervention pathway of MXSG based on these components was analyzed with network pharmacology, and it was found that the pathways related to the virus infection process were enriched in some of MXSG component targets. Simultaneously, through literature research, it was preliminarily determined that MXSG, which is an essential prescription for treating COVID-19, shared the feature of antiviral, improving clinical symptoms, regulating immune inflammation, and inhibiting lung injury. The regulatory mechanisms associated with its treatment of COVID-19 were proposed. That MXSG might directly inhibit the adsorption and replication of SARS-CoV-2 at the viral entry step. Besides, MXSG might play a critical role in inflammation and immune regulatory, that is, to prevent cytokine storm and relieve lung injury through toll-like receptors signaling pathway. Next, in this study, the regulatory effect of MXSG on inflammatory lung injury was validated through transcriptome results. In summary, MXSG is a relatively active and safe treatment for influenza and viral pneumonia, and its therapeutic effect may be attributed to its antiviral and anti-inflammatory effects.

Analysis of volatile compounds causing undesirable odors in a polypropylene - high-density polyethylene recycled plastic resin with solid-phase microextraction.

Although recycled plastics provide a low-cost and environmentally friendly alternative for many applications, their desirability is significantly limited by the presence of unpleasant odors from volatile organic compounds (VOCs). In this work, a headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) method was optimized to analyze volatile compounds from an odorous recycled plastic resin which was roughly composed of 85-90% polypropylene (PP) and 15-10% high-density polyethylene (HDPE). A large variety of aliphatic hydrocarbons and 13 additive residues were detected. Statistical tools were employed to screen the VOCs and successfully identified three components, i.e., 2,4-dimethyl-heptane, 4-methyl-octane and octamethylcyclotetrasiloxane (D4), which were significantly related to the odor intensity of the recycled plastic resin (p-values < 0.05). 2,4-Dimethyl-heptane has a strong, pungent plastic smell, which is very similar to the odor of the recycled resin. It is identified as a major source of the odor. Past relevant research has not been able to establish a direct link between an odorous compound and the undesirable odor of recycled plastic until now. 4-Methyl-octane was highly corelated to 2,4-dimethyl-heptane and somewhat contributed to the odor. D4 does not have an odor, but it may serve as an indicator of some odorous residues from personal care products.

CAR-T Cell Therapy in Cancer: Tribulations and Road Ahead.

Chimeric antigen receptor- (CAR-) T cell therapy is one of the most recent innovative immunotherapies and is rapidly evolving. Like other technologies, CAR-T cell therapy has undergone a long development process, and persistent explorations of the actions of the intracellular signaling domain and make several improvements have led to the superior efficacy when anti-CD19 CAR-T cell treatments in B cell cancers. At present, CAR-T cell therapy is developing rapidly, and many clinical trials have been established on a global scale, which has great commercial potential. This review mainly describes the toxicity of CAR-T cell therapy and the challenges of CAR-T cells in the treatment of solid tumors, and looks forward to future development and opportunities for immunotherapy and reviews major breakthroughs in CAR-T cell therapy.

Study on the mechanisms of "Xiaoerhuashi Pill, XP" in intervening the health status of high-calorie diet animals.

ETHNOPHARMACOLOGICAL RELEVANCE: "Xiaoerhuashi Pill, XP", with a history of 30 years in China, was included in the first part of the 2015 edition of the Chinese Pharmacopoeia and is widely used in the treatment for pediatric diseases in clinical application. Its main indications include the accumulation of heat caused by food stagnation in children, which has the effect of digestive stagnation and purge heat to relax the bowels. AIM OF THE STUDY: High-calorie diet, closely related to the occurrence and development of multiple diseases, is an unhealthy status of life. However, there is no effective intervention in clinic. Thus, based on animal experiments and bioinformatics, this study aims to explore the potential mechanisms of action of Chinese patent medicine- "Xiaoerhuashi Pill, XP" in the intervention of high-calorie diet. MATERIALS AND METHODS: A high-calorie diet model was prepared by 3-week-old rats. The defecation and intestinal mucosal morphology were observed after intragastric administration of "Xiaoerhuashi Pill, XP". The components of "Xiaoerhuashi Pill, XP" were obtained by chromatography-mass spectrometry, with the corresponding targets obtained by database and target fishing. The key effects substances were obtained by molecular docking, with the obtaining of the ore pathway of "Xiaoerhuashi Pill, XP" in intervention of high-calorie diet based on the enrichment analysis. RESULTS: "Xiaoerhuashi Pill, XP" can actively interfere with defecation and intestinal mucosal structures in high-calorie diet animals. A total of 37 substances were identified in the pediatric digestion solution, and 356 target proteins were mapped, 25 of which were associated with a high-calorie diet. Overall, the analysis shows that the highest degree of integration was quercetin and PON1 protein, with the highest enrichment of insulin resistance pathway. CONCLUSION: "Xiaoerhuashi Pill, XP" can intervene in the health status of high-calorie diet animals. Integration of quercetin and PON1 protein can regulate lipid levels, which may be the key mechanisms of action in "Xiaoerhuashi Pill, XP". The mechanisms, more specifically, may be related to the regulation of pancreas islet function, thus providing a reference for the clinical application of "Xiaoerhuashi Pill, XP", clinical intervention of high-calorie diet and new drug development.

Effect of High Calorie Diet on Intestinal Flora in LPS-Induced Pneumonia Rats.

Intestinal flora plays an important role in inflammatory response to systemic or local organs of its host. High calorie diet has been shown to aggravate the condition of pneumonia and delay recovery, especially in children. However, the underlying mechanisms remain unclear. This study placed SPF rats in a conventional environment, high calorie diet or LPS atomization was performed respectively or combined. Analysis of high-throughput sequencing of intestinal content combined with animal weight, organ index, serum inflammatory factors indicators and bioinformatics found that after pulmonary infection combined with a high-calorie diet, rats showed significant changes such as weight loss and increased lung weight index, and their lung and intestinal tissues showed more obvious inflammatory changes. And its gut flora structure suggests, the abundance of Leuconostocaceae in significantly reduced; abundance of Staphylococcus, Planococcaceae, Staphylococcus, Staphylococcaceae, Bacillales, Gemellales and Aerococcus significant increased. The study showed that high calorie diet and LPS atomization synergistically promoted pneumonia process in rat pups, which is related to changes in structure of intestinal flora. It is worth noting that pneumonia rats fed by convention diet also causing intestinal flora imbalance.

Circular RNAs: A novel target among non­coding RNAs with potential roles in malignant tumors (Review).

Circular RNAs (circRNAs) are a class of non­coding RNAs that are generated via alternative back­splicing, which connects the terminal 5' and 3'ends. Due to their unique loop structure, circRNAs are resistant to ribonucleases and more stable than linear RNAs. In vivo, they are usually highly conserved and stably expressed in tissue/developmental­stage­specific manners. Generally, circRNAs function as microRNA sponges and splicing regulators, as well as in protein binding and transcription. Some circRNAs contain open reading frames with internal ribosomal entry site elements and can thus encode specific proteins. Previously, circRNAs were thought to be erroneous splicing products or by­products of mRNA splicing. With the development of the next­generation sequencing techniques, it has become increasingly clear that circRNAs are abundantly widespread in eukaryotes and that they play significant roles in malignant tumor progression. The present review briefly introduces the biogenesis and functions of circRNAs, as well as summarizes recent research in several common malignancies. The present review also addresses the prospects of circRNAs in clinical applications.

Preparation and Characterization of Microcellulose and Nanocellulose Fibers from Artemisia Vulgaris Bast.

Artemisia vulgaris is an economic plant that is spreading widely in central China. Its unused bast generates a large amount of biomass waste annually. Utilizing the fibers in Artemisia vulgaris bast may provide a new solution to this problem. This research attempts to strengthen the understanding of Artemisia vulgaris by analyzing its fiber compositions and preparing micro- and nano-cellulose fibers, which can be used as raw materials for composites. In this work, Artemisia vulgaris bast powder (AP) and microcellulose and nanocellulose fibers (AMFs and ANFs) were produced and characterized by optical microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TG), and bacteriostatic test. The results indicated that cellulose, hemicellulose, and lignin were the main components in the Artemisia vulgaris bast. The cellulose content reached 40.9%. The Artemisia vulgaris single fibers were microcellulose fibers with an average length of 850.6 µm and a diameter of 14.4 µm. Moreover, the AMF had considerable antibacterial ability with an antibacterial ratio of 36.6%. The ANF showed a length range of 250-300 nm and a diameter of 10-20 nm, and it had a higher crystallinity (76%) and a lower thermal stability (initial degradation temperature of 183 °C) compared with raw ANF (233 °C). This study provides fundamental information on Artemisia vulgaris bast cellulose for its subsequent utilization.