Ecological effect of microplastics on soil microbe-driven carbon circulation and greenhouse gas emission: A review.

Soil organic carbon (SOC) pool, the largest part of terrestrial ecosystem, controls global terrestrial carbon balance and consequently presented carbon cycle-climate feedback in climate projections. Microplastics, (MPs, <5 mm) as common pollutants in soil ecosystems, have an obvious impact on soil-borne carbon circulation by affecting soil microbial processes, which play a central role in regulating SOC conversion. In this review, we initially presented the sources, properties and ecological risks of MPs in soil ecosystem, and then the differentiated effects of MPs on the component of SOC, including dissolved organic carbon, soil microbial biomass carbon and easily oxidized organic carbon varying with the types and concentrations of MPs, the soil types, etc. As research turns into a broader perspective, greenhouse gas emissions dominated by the mineralization of SOC coming into view since it can be significantly affected by MPs and is closely associated with soil microbial respiration. The pathways of MPs impacting soil microbes-driven carbon conversion include changing microbial community structure and composition, the functional enzyme's activity and the abundance and expression of functional genes. However, numerous uncertainties still exist regarding the microbial mechanisms in the deeper biochemical process. More comprehensive studies are necessary to explore the affected footprint and provide guidance for finding the evaluation criterion of MPs affecting climate change.

Enhanced biotoxicity by co-exposure of aged polystyrene and ciprofloxacin: the adsorption and its influence factors.

Microplastics (MPs), as emerging contaminants, usually experience aging processes in natural environments and further affect their interactions with coexisted contaminants, resulting in unpredictable ecological risks. Herein, the effect of MPs aging on their adsorption for coexisting antibiotics and their joint biotoxicity have been investigated. Results showed that the adsorption capacity of aged polystyrene (PS, 100 d and 50 d) for ciprofloxacin (CIP) was 1.10-4.09 times higher than virgin PS due to the larger BET surface area and increased oxygen-containing functional groups of aged PS. Following the increased adsorption capacity of aged PS, the joint toxicity of aged PS and CIP to Shewanella Oneidensis MR-1 (MR-1) was 1.03-1.34 times higher than virgin PS and CIP. Combined with the adsorption process, CIP posed higher toxicity to MR-1 compared to aged PS due to the rapid adsorption of aged PS for CIP in the first 12 h. After that, the adsorption process tended to be gentle and hence the joint toxicity to MR-1 was gradually dominated by aged PS. A similar transformation between the adsorption rate and the joint toxicity of PS and CIP was observed under different conditions. This study supplied a novel perception of the synergistic effects of PS aging and CIP on ecological health.

Is Operative Management Effective for Non-Bacterial Diffuse Sclerosing Osteomyelitis of the Mandible?

PURPOSE: Operative management has been reported to show varying degrees of therapeutic effects for non-bacterial diffuse sclerosing osteomyelitis of the mandible (DSOM). The purpose of this study was to retrospectively analyze and summarize the operative outcomes for non-bacterial DSOM. METHODS: In this retrospective cohort study, patients with non-bacterial DSOM who received operative treatment were enrolled at the Peking University Hospital of Stomatology between 2012 and 2019. The primary predictor variables were the type of operative treatment and number of operations. The outcome variables were operative outcomes (symptom relief or ineffective) and time to recurrent symptoms after operations. Other study variables were demographics, including sex, age, and non-bacterial DSOM onset time. The χ2 test and Kaplan-Meier model were used to evaluate differences. RESULTS: The sample was composed of 72 patients with a mean age at onset of 26.1 ± 17.8 years and showed a female predilection. Decortication was performed for 68 patients with non-bacterial DSOM, and 4 patients underwent segmental mandibulectomy. Symptom relief was achieved in 37 (54.4%) patients after the first decortication, and the median time to symptom recurrence was 2.0 months. Furthermore, the longest time to symptom recurrence was not more than 6 months in all patients. Among the 4 patients who underwent segmental mandibulectomy, 2 who received fibula repair experienced recurrence of symptoms at 4 and 5 months after the operations, respectively, and their normal mandible and the transplanted fibula also presented with imaging manifestations of osteomyelitis. CONCLUSIONS: Decortication and segmental mandibulectomy were not effective for non-bacterial DSOM. This finding is consistent with the results of other reports, and this condition may be best managed non-operatively by rheumatologists.

Lytic peptide-grafted beta-cyclodextrin polymer based nano-scaled drug delivery system with enhanced camptothecin anti-cancer efficacy.

The aqueous solubility of drug molecules is closely related to its bioactivity like bioavailability and subsequent therapeutic index, especially in the case of hydrophobic drugs like camptothecin (CPT), a potential broad-spectrum anti-cancer agent. Enhanced anti-cancer activity and selectivity of CPT are equally important. Inspired by host-guest effect and drug combination regimen, we developed a novel tumor lytic peptide incorporated drug delivery system by forming beta-cyclodextrin polymer (BCDp) based inclusion complex in nano-scaled size. In this study, BCDp formed inclusion complex with CPT and then a lytic-type peptide (ZH) was grafted. The resulting combinational formulation of BCDp, CPT and ZH, named as ZH-BCDp-CPT inclusion complex, demonstrated greater solubility resulting from its nano-scaled size, amorphous solid state and inclusion structure. Moreover, ZH facilitated quick internalization of conjugated drug via cell membrane lysis, leading to efficient intracellular drug delivery. This novel drug formulation was featured with prolonged circulation, enhanced anti-cancer efficacy, selectivity, anti-cell migration activity and better biocompatibility in comparison with crude CPT and binary BCDp-CPT inclusion complex, all of which were attributed to a cooperative action between ZH and BCDp-CPT inclusion complex. Our results suggested ZH-BCDp-CPT inclusion complex induced cell apoptosis by up-regulation of Bax and P53 and down-regulation of Bcl-2, primarily involved in the mitochondrial pathways.

Effects of polystyrene microbeads on cytotoxicity and transcriptomic profiles in human Caco-2 cells.

Microplastics (MPs) pollution is a global paradigm that raises concern in relation to environment and human health. In order to investigate the molecular toxicity mechanisms of MPs, transcriptomic analyses were performed on in vitro Caco-2 cell model. After observing that polystyrene microplastics (PS-MPs) decreased cell viability in a dose-dependent manner, the responsible genes and involved pathways that might make contribution to PS-MBs-induced toxicity to Caco-2 cells were identified with Illumina RNA seq. A total of 442 genes including, 210 up-regulated ones and 232 down-regulated ones, showed differential expression after treatment by PS-MPs with a concentration of 12.5 mg L-1 or 50.0 mg L-1 for 24 hours. Gene Ontology (GO) annotation enriched unigenes can be grouped into three separated clusters: cellular component (CC), biological process (BP), and molecular function (MF). The dominate pathways related to NF-κB, MAPK signaling, cytokine-cytokine receptor interaction, and toll-like receptor were strongly influenced by PS-MBs. These pathways are involved in modulating cell inflammatory and proliferation. The qPCR were applied to investigate the transcriptional level of five proliferation related genes (Ras, ERK, MER, CDK4, Cyclin D1) and four inflammation related genes (TRPV1, iNOS, IL-1ß, IL-8), and the results were consistent with RNA-seq data. This study has provided new insight into the understanding of the toxicity effects of PS-MBs-induced intestinal inflammatory diseases.

Denture use and risk for cardiometabolic disease: observational and Mendelian randomization analyses.

AIMS: Denture use may potentially increase the risk of cardiometabolic diseases (CMDs), but the casual relevance and strength of the associations are currently unknown. METHODS AND RESULTS: A total of 495 938 participants from the UK Biobank were included in the observational analyses. Linkage disequilibrium score (LDSC) regression and Mendelian randomization analyses were employed to estimate genetic correlation and the associations between the genetic liability for denture use with coronary artery disease, myocardial infarction, heart failure (HF), any stroke (AS), ischaemic stroke, haemorrhagic stroke, type 2 diabetes (T2D), and related clinical risk factors. In observational analysis, denture use was associated with 14-25% higher risks of various CMDs. The LDSC analysis found that denture use showed a positive genetic correlation with CMDs (rg 0.21-0.38). Genetic liability for denture use was associated with an elevated risk of HF [odds ratio: 1.49 (1.20-1.83)] and T2D [1.11 (1.01-1.24)]. By integrating genetic summary data of denture use with the sum of decayed, missing, and filled tooth surfaces (DMFS), a clinical measure of dental caries obtained from an independent source, genetically determined denture use/DMFS was also associated with an elevated risk of AS [1.21 (1.04-1.40)]. Furthermore, genetically predicted denture use/DMFS was significantly associated with established cardiometabolic risk factors, including HDL cholesterol, triglycerides, waist circumference, waist-to-hip ratio, and height. CONCLUSION: Our study supported potential causal associations between the genetic liability for denture use and risks for HF, AS, T2D, and related clinical risk factors. These findings may inform prevention and intervention strategies targeting dental diseases and CMDs.

This study examined the association of denture use with cardiometabolic diseases (CMDs) and related clinical risk factors through Mendelian randomization analyses using data from UK Biobank and published consortia. Genetic liability for denture use was associated with an 11­49% higher risk of heart failure, stroke, and type 2 diabetes.The potential causal relationship between denture use and CMDs was further strengthened by the associations of denture use with HDL cholesterol, triglycerides, waist circumference, waist-to-hip ratio, and height, which are among the major risk factors of CMDs.

Multiple perspectives reveal the gut toxicity of polystyrene microplastics on Eisenia fetida: Insights into community signatures of gut bacteria and their translocation.

The gut is the primary pathway by which soil animals are exposed to microplastics (MPs). However, the gut toxicity of MPs has not been elucidated in earthworms. Herein, we aimed to study the gut toxicity (e.g., gut barrier dysfunction, gut bacterial translocation, and pathogen invasion) of polystyrene microplastics (PS-MPs) on Eisenia fetida and its relationship with gut bacteria. We found that PS-MPs exposure caused gut barrier damage to Eisenia fetida. This damage included apparent injury of gut epithelial cells and significantly lower transcription levels of genes coding for gut tight junction (TJ)-related proteins. We then observed significantly increased levels of bacterial lipopolysaccharide (LPS) and gut bacterial load, indicating the occurrence of gut bacterial translocation and related barrier damage. Subsequently, antibacterial immune responses were activated and accompanied by a failure of the antioxidant defense system, indicating that pathogen invasion might occur. Gut barrier damage could weaken host selective pressures (deterministic process) on gut bacteria, such as particular pathogens. Indeed, members of Proteobacteria, e.g., Aeromonas and Escherichia/Shigella, regarded as potential opportunistic pathogens, were remarkable signatures of groups exposed to PS-MPs. These potential opportunistic gut bacteria were pivotal contributors to gut TJ damage and gut bacterial translocation resulting from PS-MPs exposure. In addition, the gut bacterial networks of PS-MPs exposure groups were more uncomplicated than those of the control group, but more negative interactions were easy to observe. In conclusion, our work sheds light on the molecular mechanism of earthworm gut toxicity caused by PS-MPs exposure and provides a prospective risk assessment of MPs in soil ecosystems.

Designing ultrafine PdCo alloys in mesoporous silica nanospheres with peroxidase-like activity and catalase-like activity.

Nanomaterial-based artificial enzyme mimetics have attracted increasing attention because of their robust stability, adjustable activity, and cost-effectiveness. In this study, we developed a simple and effective method for the synthesis of highly dispersed ultrafine PdCo alloys with peroxidase- and catalase-like activities. The aberration-corrected transmission electron microscopy analysis verified that the cyanogel precursor in the mesoporous silica nanospheres (MSNs) was converted to PdCo alloy in NH3 at a high temperature. The PdCo alloy was homogenously distributed in MSNs as ultrafine and monodispersed particles. By selectively removing the Co species from the binary alloy through an acid-leaching approach, the role of each component in the enzyme-like mimetics was systematically studied. Using glutathione (GSH) as the model analyte, the potential application of PdCo@MSNs in GSH detection from complex cell media was confirmed via colorimetric assay. The ultrafine alloy size, double mimetic activities, and abundant loading space of PdCo@MSNs make them promising not only in clinical diagnosis but also in overcoming hypoxia-induced photodynamic therapy resistance in tumor treatment.

Overexpressing CCW12 in Saccharomyces cerevisiae enables highly efficient ethanol production from lignocellulose hydrolysates.

A Saccharomyces cerevisiae strain CCW12OE was constructed by overexpressing CCW12 in a previously reported strain WXY70 harboring six xylose utilization genes. CCW12OE produced an optimal ethanol yield of 98.8% theoretical value within 48 h in a simulated corn stover hydrolysate. CCW12OEwas comprehensively evaluated for ethanol production in Miscanthus, maize and corncob hydrolysates, among which a 96.1% theoretical value was achieved within 12 h in corncob hydrolysates. Under normal growth conditions, CCW12OE did not display altered cell morphology; however, in the presence of acetate, CCW12OE maintained relatively intact cell structure and increased cell wall thickness by nearly 50%, while WXY70 had abnormal cell morphology and reduced cell wall thickness by nearly 50%. Besides, CCW12OE had higher fermentation capacity than that of WXY70 in undetoxified and detoxified hydrolysates with both aerobic and anaerobic conditions, demonstrating that CCW12 overexpression alone exhibits improved stress resistance and better fermentation performance.

Gut region influences the diversity and interactions of bacterial communities in pikas (Ochotona curzoniae and Ochotona daurica).

The mammalian microbial communities in the gastrointestinal tract (GIT) play important roles in host nutrition and health. However, we still lack an understanding of how these communities are organized across GIT in natural environments. Here, using 16S rRNA gene sequencing, we analyzed the bacterial community diversity, network interactions and ecosystem stability across five gut regions (mouth, stomach, small intestine, cecum and colon) emanating from two common pika species in China, including Plateau pikas (Ochotona curzoniae) inhabiting high-altitude regions, as well as Daurian pikas (O. daurica) occupying low-altitude areas. The relative abundances of dominant Bacteroidetes and Firmicutes exhibited an increasing trend from mouth to colon. Cecum and colon harbored higher bacterial diversity compared with other anatomical regions. Gut region significantly influenced the structure of bacterial communities in the GIT. Network analysis indicated that topological features showed marked variations among gut regions. Interestingly, the ecosystem stability of bacterial communities increased gradually from mouth to colon. Our results suggest that gut region influences the diversity, structure and network interactions of bacterial communities in pikas. For hindgut-fermenting herbivorous mammals, relatively higher bacterial diversity and ecosystem stability in the cecum may provide a favorable condition for the fermentation of indigestible plant polysaccharides.

Synthesis and Properties of Hemostatic and Bacteria-Responsive in Situ Hydrogels for Emergency Treatment in Critical Situations.

Immediate hemorrhage control and infection prevention are pivotal for saving lives in critical situations such as battlefields, natural disasters, traffic accidents, and so on. In situ hydrogels are promising candidates, but their mechanical strength is often not strong enough for use in critical situations. In this study, we constructed three hydrogels with different amounts of Schiff-base moieties from 4-arm-PEG-NH2, 4-arm-PEG-NHS, and 4-arm-PEG-CHO in which vancomycin was incorporated as an antimicrobial agent. The hydrogels possess porous structures, excellent mechanical strength, and high swelling ratio. The cytotoxicity studies indicated that the composite hydrogel systems possess good biocompatibility. The Schiff bases incorporated improve the adhesiveness and endow the hydrogels with bacteria-sensitivity. The in vivo hemostatic and antimicrobial experiments on rabbits and pigs demonstrated that the hydrogels are able to aid in rapid hemorrhage control and infection prevention. In summary, vancomycin-loaded hydrogels may be excellent candidates as hemostatic and antibacterial materials for first aid treatment of the wounded in critical situations.

Fabrication of graphene-platinum nanocomposite for the direct electrochemistry and electrocatalysis of myoglobin.

In this paper a platinum (Pt) nanoparticle decorated graphene (GR) nanosheet was synthesized and used for the investigation on direct electrochemistry of myoglobin (Mb). By integrating GR-Pt nanocomposite with Mb on the surface of carbon ionic liquid electrode (CILE), a new electrochemical biosensor was fabricated. UV-Vis absorption and FT-IR spectra indicated that Mb remained its native structure in the nanocomposite film. Electrochemical behaviors of Nafion/Mb-GR-Pt/CILE were investigated with a pair of well-defined redox peak appeared, which indicated that direct electron transfer of Mb was realized on the underlying electrode with the usage of the GR-Pt nanocomposite. The fabricated electrode showed good electrocatalytic activity to the reduction of trichloroacetic acid in the linear range from 0.9 to 9.0 mmol/L with the detection limit as 0.32 mmol/L (3σ), which showed potential application for fabricating novel electrochemical biosensors and bioelectronic devices.