Biofilms have been extensively studied in aquatic and clinical environments. However, the complexity of edaphic microenvironment hinders the advances toward understanding the environmental ...functionalities and ecological roles of soil biofilms. In this work, artificial soil was employed to investigate the soil biofilm formation and corresponding impacts on community structure and microbial activities. Our results showed that extracellular polymeric substances (EPS) production was significantly enhanced and micro-meter sized cell aggregates formed with high glucose amendment. Biofilm development exhibited significant effects on the soil microbial processes. 16S rRNA gene sequencing demonstrated the soils with biofilms and free-living cells shared similar microbial communities. But the Shannon diversity and evenness indices of communities with soil biofilms were significantly enhanced by 18.2% and 17.1%. The soil with biofilms also revealed a rapid response to nutrient provision and robust microbial activity, which consumed 65.4% more oxygen in the topsoil (0–1.5 mm). Kinetic respiration analysis showed that the enhanced metabolic activity was attributed to 23-times more active microbes in soil biofilms. In summary, this study revealed that soil biofilms can sustain a diverse and robust community to drive soil biogeochemical processes.
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•High nutrient supply induced less microbial biomass growth, enhanced EPS production and soil biofilm formation.•The microbial diversity and evenness of soil with biofilms was significantly higher than that with free-living cells.•The soil with biofilms revealed an elevated microbial respiration rate and a rapid response to nutrient amendment.•Soil biofilm sustained 40-times more active microbes than that with free-living cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Bacterial biofilms are surface-adherent microbial communities in which individual cells are surrounded by a self-produced extracellular matrix of polysaccharides, extracellular DNA (eDNA) and ...proteins. Interactions among matrix components within biofilms are responsible for creating an adaptable structure during biofilm development. However, it is unclear how the interactions among matrix components contribute to the construction of the three-dimensional (3D) biofilm architecture.
DNase I treatment significantly inhibited Bacillus subtilis biofilm formation in the early phases of biofilm development. Confocal laser scanning microscopy (CLSM) and image analysis revealed that eDNA was cooperative with exopolysaccharide (EPS) in the early stages of B. subtilis biofilm development, while EPS played a major structural role in the later stages. In addition, deletion of the EPS production gene epsG in B. subtilis SBE1 resulted in loss of the interaction between EPS and eDNA and reduced the biofilm biomass in pellicles at the air-liquid interface. The physical interaction between these two essential biofilm matrix components was confirmed by isothermal titration calorimetry (ITC).
Biofilm 3D structures become interconnected through surrounding eDNA and EPS. eDNA interacts with EPS in the early phases of biofilm development, while EPS mainly participates in the maturation of biofilms. The findings of this study provide a better understanding of the role of the interaction between eDNA and EPS in shaping the biofilm 3D matrix structure and biofilm formation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this paper, a novel broadband hybrid piezoelectric-electromagnetic-electrostatic energy harvester with frequency up-conversion is proposed to improve the harvesting bandwidth and energy conversion ...efficiency. The designed device generates vibration energy with much higher frequency than ambient vibration frequency, which uses the magnet to impact periodically on the piezoelectric cantilever with the top electrode of electrostatic element. The dynamic model of the hybrid energy harvester is established, and performances are experimental tested under the sinusoidal excitation and practical application environment. The results show that multi-mechanisms composite structure can realize the complementary advantages of electrostatic-piezoelectric-electromagnetic mechanisms and improve the energy conversion efficiency effectively compared with a single harvesting mechanism. The fabricated harvester can output electric energy in the frequency range of 1–38 Hz, which significantly reduces frequency dependence, and the maximum power is measured to be 11.7 mW and 12 mW during cycling and walking respectively, which is the sum of the power generated by three different elements. Furthermore, the fabricated prototype can also light up six light-emitting diodes (LEDs) simultaneously when handy shaking.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•NPs within low concentration threshold significantly promote biofilm formation.•EPS is critical for biofilm tolerance of NPs.•Cells in mature biofilm are more resistant to NPs than ...cells at other stages.•Low level of NPs stimulated the release of biofilm-related signaling molecules.•High content NPs exposure induced genotoxicity and upregulated antioxidant genes.
Elucidating the effects of nanoparticles (NPs) on key bacterial functions not only deepens our understanding of nano-toxicity mechanisms, but also guides us in the design criteria for manufacturing safe nanomaterials. In this study, bacterial growth, biofilm development and the expression of biofilm-related genes were monitored in Pseudomonas putida KT2440, a plant-beneficial bacterium, following exposure to ZnO NPs. Low concentrations of NPs (0.5–30 mg L−1) significantly promoted bacterial growth and biofilm formation, while higher concentrations (>30 mg L−1) significantly inhibited biofilm formation. Confocal laser scanning microscopy revealed that microscope slides coated with 0.5 mg L−1 of ZnO NPs showed enhanced bacterial colonization and biomass production, but at higher concentrations (250 mg L−1), biomass production was about 11 times lower than that of the substrate without NPs. Increased protein and sugar contents of the biofilm matrix corroborated the stimulating effects of low concentrations of ZnO NPs. Physiological data were supported by changes in the expression of genes associated with oxidative stress and biofilm development. ZnO NPs at 0.5 mg L−1 stimulated the expression of quorum sensing, lipopolysaccharide biosynthesis, and antibiotic resistance genes; high concentrations of ZnO NPs (250 mg L−1) down-regulated biofilm formation-related genes and up-regulated antioxidant genes. Our results indicate that long-term release of low concentrations of ZnO NPs to the environment would promote undesired biofilm formation and increased resistance to antibiotics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The semiconductor antimony sulfide (Sb2S3) is a potential absorber materials for the top sub-cell of Si-based tandem solar cells because of its appropriate band-gap, simple binary composition, ...nontoxic elements, and long-term stability. In this study, polycrystalline Sb2S3 films were fabricated by post-annealing of radio frequency (RF) magnetron sputtered precursors using an Sb2S3 target. The effects of the post-annealing temperature and atmosphere on Sb2S3 film properties and device performances were investigated. A high-performance device having a 2.41% power conversion efficiency was obtained by making use of a uniform Sb2S3 absorber layer. This preliminary experimental study shows that Sb2S3 thin films could be used as top sub-cell absorber materials for third-generation high efficiency, stable, and environmentally friendly Sb2S3/Si tandem solar cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
β-lactam antibiotics are the most frequently used drugs and the most common drugs that cause allergic reactions in pediatrics. The occurrence of some allergic reactions can be predicted by skin ...testing, especially severe adverse reactions such as anaphylactic shock. Thus, penicillin and cephalosporin skin tests are widely used to predict allergic reactions before medication in pediatrics. However, false-positive results from skin tests were more often encountered in pediatrics than in adults. In fact, many children labeled as allergic to β-lactam are not allergic to the antibiotic, leading to the use of alternative antibiotics, which are less effective and more toxic, and the increase of antibiotic resistance. There has been controversy over whether β-lactam antibiotics should be tested for skin allergies before application in children. Based on the great controversy in the implementation of β-lactam antibiotic skin tests, especially the controversial cephalosporin skin tests in pediatrics, the mechanism and reasons of anaphylaxis to β-lactam antibiotics, the significance of β-lactam antibiotic skin tests, the current state of β-lactam antibiotic skin tests at home and abroad, and the problems of domestic and international skin tests were analyzed to determine a unified standard of β-lactam antibiotic skin tests in pediatrics to prevent and decrease adverse drug reactions, avoid waste of drugs, and a large amount of manpower and material resource consumption.
Breast cancer is an important women's malignancy with high cancer-related deaths worldwide. Drug resistance lowers the treatment efficacy in this malignancy. This study aimed to explore the ...underlying mechanisms of histone deacetylase (HDAC) inhibitor trichostatin A (TSA) to overcome resistance to tamoxifen in breast cancer cells.
Tamoxifen-resistance in MCF-7 breast cancer cells was simulated. MTT assay was used to detect the cytotoxic effects of HDAC inhibitor and PI3K inhibitor on the cancer cells. Trans-well assay was applied to evaluate the invasion and migration of the treated cancer cells. Flow cytometer assay was also applied to evaluate cell cycle phases in the treated cancer cells. Finally, expression of vascular endothelial growth factor (VEGF), E-cadherin, Vimentin, phosphorylated phosphatidylinositol kinase (p-PI3k), phosphorylated protein kinase B (p-AKT), and phosphorylated mammalian target protein of rapamycin (p-mTOR) was evaluated by western blotting.
The obtained results indicated that HDAC inhibitor treatments significantly decreased viability, migration, and invasion in the cancer cells. Furthermore, the frequency of the treated cancer cells significantly increased in the S phase as well as significantly decreasing in the G2/M phase of the cell cycle. Moreover, HDAC inhibitor modified levels of VEGF, E-cadherin, Vimentin, p-PI3k, p-AKT, and p-mTOR proteins. However, HDAC inhibitor combined with PI3K inhibitor exerts more profound effects on the cancer cells as compared to HDAC inhibitor monotherapy.
HDAC inhibitors inhibited the survival of breast cancer drug-resistant cells, invasion, migration, and angiogenesis by inhibiting the PI3k/Akt/mTOR signaling pathway.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The role of microbial interactions and the underlying mechanisms that shape complex biofilm communities are poorly understood. Here we employ a microfluidic chip to represent porous subsurface ...environments and show that cooperative microbial interactions between free-living and biofilm-forming bacteria trigger active spatial segregation to promote their respective dominance in segregated microhabitats. During initial colonization, free-living and biofilm-forming microbes are segregated from the mixed planktonic inoculum to occupy the ambient fluid and grain surface. Contrary to spatial exclusion through competition, the active spatial segregation is induced by cooperative interactions which improves the fitness of both biofilm and planktonic populations. We further show that free-living Arthrobacter induces the surface colonization by scavenging the biofilm inhibitor, D-amino acids and receives benefits from the public goods secreted by the biofilm-forming strains. Collectively, our results reveal how cooperative microbial interactions may contribute to microbial coexistence in segregated microhabitats and drive subsurface biofilm community succession.
Background
For advanced tumors that lack specific oncogenic alteration and are resistant to chemotherapy, anti-angiogenesis therapy or immunotherapy or a combination of the two are the most important ...treatments. Anlotinib is a newly developed oral small molecule receptor tyrosine kinases inhibitor with the potency of inhibiting tumor angiogenesis. This was an open-label, single-arm, phase 2 study to validate the efficacy and safety of anlotinib in patients with various cancer types.
Methods
Patients with advanced malignancy who have failed previous therapies or lack effective treatment choices received daily oral administration of 12 mg anlotinib on days 1–14 every 3 weeks until disease progression, intolerable toxicity or physician decision. The primary endpoint was objective response rate (ORR).
Results
A total of 93 eligible patients with 26 different cancer types were enrolled. The overall ORR was 21.5%. The median PFS was 5.7 months and median OS was 12.0 months. The most common treatment-related AE of all grades and of grade 3 was both hypertriglyceridemia at an incidence of 40.9% and 5.4%, respectively.
Conclusions
Anlotinib exhibits objective efficacy and safety in advanced malignancy and might be a possible treatment option for many types of cancer patients who have failed prior treatment and with no optimal therapy regimen.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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