Dryland covers >35 % of the terrestrial surface and the global extent of dryland increases due to the forecasted increase in aridity driven by climate change. Due to the climate change-driven aridity ...ecosystems, deserts provide one of the most hostile environments for microbial life and survival. Therefore, a study was carried out to explore the arid deserts (exposed to severe climate change) influence on microbial (bacterial, fungal, and protist) diversity patterns, assembly processes, and co-occurrence. The results revealed that the aridity (semi-arid, arid, and hyper-arid) pattern caused distinct changes in environmental heterogeneity in desert ecosystems. Similarly, microbial diversities were also reduced with increasing the aridity pattern, and it was found that environmental heterogeneity is highly involved in affecting microbial diversities under different ecological niches. Interestingly, it was found that certain microbes, including bacterial (Firmicutes), fungal (Sordariomycetes), and protistan (Ciliophora) abundance increased with increasing aridity levels, indicating that these microbes might possess the capability to tolerate the environmental stress condition. Moreover, microbial community turnover analysis revealed that bacterial diversities followed homogenous selection, whereas fungi and protists were mostly driven by the dispersal limitation pattern. Co-occurrence network analysis showed that hyper-arid and arid conditions tightened the bacterial and fungal communities and had more positive associations compared to protists. In conclusion, multiple lines of evidence were provided to shed light on the habitat specialization impact on microbial (bacteria, fungi, and protists) communities and composition under different desert ecosystems.
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•Aridity patterns caused a substantial influence on microbial composition in deserts.•Among bacteria, Firmicutes possess resistant capabilities to hyper arid ecosystem.•Among fungi and protists, Sordariomycetes and Ciliophora abundance increased with aridity.•Bacteria followed homogenous selection while fungi and protists are majorly driven by dispersal limitations.•Hyper arid ecosystem strengthened the correlation of bacterial and fungal communities due to specific diversity abundance.
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•Novel compound 1 possessed a benzophenone skeleton with a farnesyl side chain.•The methanol and dichloromethane extractions of H. lancasteri exhibited significant antiradical effects ....•The IC50 value of compound 4 was closest to that of the positive control drug ascorbic acid.•This work provided systematic biological targeted study on antiradical activity from active extracts to novel compound.
A novel benzophenone lancasteriphenone A (1), one new natural product 2,4-dihydroxy-6-(3-methylbut-2-enoxy) phenyl-phenylmethanone (2), along with two known compounds (3 and 4) were isolated and identified from the aerial parts of Hypericum lancasteri. Their structures were elucidated by means of spectroscopic techniques. Novel compound 1 possessed a benzophenone skeleton with a farnesyl side chain. DPPH radical scavenging activities were tested to determine the antioxidant potential of the methanol extract, dichloromethane extract as well as the isolated compounds (1–4). Its methanol and dichloromethane extracts exhibited significant antiradical effect with IC50 values of 20.84 µg/mL and 60.63 µg/mL, respectively. Besides, the antiradical activitise of the compounds 1–4 from active dichloromethane extract were also tested. The DPPH radical scavenging rates of the compounds 1–4 were 33.07%, 24.59%, 17.67% and 86.56% at the concentration of 400 µmol/L, respectively, while the IC50 value (97.53 µmol/L) of compound 4 was closest to that of the positive control drug ascorbic acid (IC50 = 58.13 µmol/L). This work provided systematic biological targeted study on antioxidant activity from active extracts to novel compound, and shed a new light on the further antioxidant application research of H. lancasteri.
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•Coupled g-C3N4/TiO2 photocatalysts are synthesized by calcining TiO2 nanoparticles with urea at 350–500 °C.•The phase composition, and textural and optical properties of g-C3N4/TiO2 ...are characterized.•The photocatalytic activity of g-C3N4/TiO2 is comparatively studied under UV, visible, and simulated solar light irradiation.•The charge carrier transfer in g-C3N4/TiO2 heterojunction is revealed.
g-C3N4/TiO2 derived from the surface modification of TiO2 by calcination with urea has been widely studied as a “visible-light-active” photocatalyst for environmental remediation. However, few attentions have been paid to the structure characterization and the photocatalytic properties of the resultant nanocomposite photocatalysts under a practical sunlight irradiation. Here we employ various characterization techniques, including TGA, XRD, TEM, XPS, UV–vis spectrum, and N2-sorption analysis to characterize the evolutions in phase crystal structure, microstructure and optical properties of g-C3N4/TiO2 nanohybrids synthesized through calcining a mechanical mixture of urea and Evonik Aeroxide P-25 TiO2 (P25) at 350–500 °C. The thermal pyrolysis of urea leads to the surface decoration of TiO2 with graphitic carbon nitrate (g-C3N4) at temperatures above 400 °C. The photocatalytic properties of the resultant g-C3N4/TiO2 nanoparticles are evaluated through photocatalytic decoloration of methylene blue (MB) and reduction of Cr (VI) to Cr (III) under visible (420 nm), UV (365 nm), and simulated solar light irradiations. The nanohybrid photocatalysts, as most previous studies reported, show much higher photocatalytic activity under visible light irradiation than the single-component counterparts, i.e. P25 or g-C3N4. However, under solar and UV irradiation, no considerable improvements are found, which is caused by the decrease in redox potential upon interfacial charge carrier transfer between g-C3N4 and TiO2. Moreover, g-C3N4/TiO2 shows an ultralow photocatalytic activity in Cr (VI) reduction. The surface modification with organic g-C3N4 is assumed to tune the surface properties (e.g. hydrophilicity) of TiO2. Our results demonstrate that photocatalytic activity in UV range is as important as that in visible range, and developing efficient “solar” photocatalysts should balance the photocatalytic activities at both ranges since they might be incompatible with each other.
•Down-regulation of intracellular ROS decreases the cytotoxicity of cisplatin in TSCC cells.•Down-regulation of intracellular ROS decreases the apoptosis induced by LPS combination with CDDP in ...CAL27/CDDP cells.•Down-regulation of intracellular ROS decreases the autophagy induced by LPS combination with CDDP in CAL27/CDDP cells.•Down-regulation of intracellular ROS attenuates apoptosis and autophagy via regulating the p38MAPK/mTOR pathway in CAL27/CDDP cells.
Cisplatin is one of the most widely used anticancer agents for patients with tongue squamous cell carcinoma (TSCC), but its efficacy is limited by chemoresistance. Accumulated evidence has demonstrated that reactive oxygen species (ROS) plays a critical role in multiple tumor chemotherapy resistance. In the present study, we aimed to investigate the role of ROS in cisplatin resistance of TSCC and explore its underlying molecular mechanism in vitro. Our results showed that pre-treatment with ROS scavenger N-acetylcysteine reduced cisplatin-induced cytotoxicity, autophagy, and apoptosis in TSCC cells. Down-regulation of intracellular ROS attenuated apoptosis and autophagy of TSCC cisplatin-resistant CAL27/CDDP cells by reversing the inhibition of p38MAPK/mTOR pathway. Taken together, these findings suggest that down-regulation of intracellular ROS reduces the cytotoxicity of cisplatin by inhibiting apoptosis and autophagy in TSCC cells involving p38MAPK/mTOR mediated pathway. Low intracellular ROS levels may be one of the main mechanisms of cisplatin resistance in TSCC.
Advanced organic vapor sensors that simultaneously have high sensitivity, fast response, and good reproducibility are required. Herein, flexible, robust, and conductive vapor-grown carbon fibers ...(VGCFs)-filled polydimethylsiloxane (PDMS) porous composites (VGCFs/PDMS sponge (CPS)) with multilevel pores and thin, rough, and hollows wall were prepared based on the sacrificial template method and a simple dip-spin-coating process. The optimized material showed outstanding mechanical elasticity and durability, good electrical conductivity and hydrophobicity, as well as excellent acid and alkali tolerance. Additionally, CPS exhibited good reproducible sensing behavior, with a high sensitivity of ~1.5 × 10
s
for both static and flowing organic vapor, which was not affected in cases such as 20% squeezing deformation or environment humidity distraction (20~60% RH). Interestingly, both the reproducibility and sensitivity of CPS were better than those of film-shaped VGCFs/PDMS (CP), which has a thickness of two hundred microns. Therefore, the contradiction between the reproducibility and high sensitivity was well-solved here. The above excellent performance could be ascribed to the unique porous structures and the rough, thin, hollow wall of CPS, providing various gas channels and large contact areas for organic vapor penetration and diffusion. This work paves a new way for developing advanced vapor sensors by optimizing and tailoring the pore structure.
Materials with tunable long persistent luminescence (LPL) properties have wide applications in security signs, anti‐counterfeiting, data encrypting, and other fields. However, the majority of ...reported tunable LPL materials are pure organic molecules or polymers. Herein, a series of metal‐organic coordination polymers displaying color‐tunable LPL were synthesized by the self‐assembly of HTzPTpy ligand with different cadmium halides (X=Cl, Br, and I). In the solid state, their LPL emission colors can be tuned by the time‐evolution, as well as excitation and temperature variation, realizing multi‐mode dynamic color tuning from green to yellow or green to red, and are the first such examples in single‐component coordination polymer materials. Single‐crystal X‐ray diffraction analysis and theoretical calculations reveal that the modification of LPL is due to the balanced action from single molecule and aggregate triplet excited states caused by an external heavy‐atom effect. The results show that the rational introduction of different halide anions into coordination polymers can realize multi‐color LPL.
By delicate design of coordination polymers incorporating different halogens, multi‐mode color‐tunable long persistent luminescence (LPL) from green to yellow or green to red was possible. The LPL emission colors can be tuned by time, excitation, and temperature, revealing the counter‐balanced mechanisms from single‐molecule and aggregate triplet excited states resulting from an external heavy‐atom effect.
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•A binary P25-LiOH hydrothermal system is developed for P25 microstructure study.•P25 mainly contains free nanoparticle with single anatase or rutile phase.•Only 15.9% rutile forms ...heterojunctioned structure with anatase.
Evonik Aeroxide P25 (formerly Degussa P25) is a flame-made multiphasic TiO2 nanoparticles containing anatase and rutile, as well as a small amount of amorphous TiO2. The past decades have witnessed the wide applications of P25 as a benchmark material for studying photocatalytic mechanism, materials and process. However, controversy remains regarding the microstructure of anatase and rutile: do they interwoven forming heterojunction structure or exist individually? To clarify it, we selected a medium alkaline, LiOH to erode bare P25 under a mild hydrothermal condition. Since rutile presents much higher resistances towards dissolution by LiOH than anatase, it is reasonable to find during hydrothermal reaction that the ratio of anatase to rutile (A/R) gradually decrease if they exist individually. Reversely, the A/R value gradually increases at the beginning of the hydrothermal reaction, implying that rutile shows high activity towards dissolution and phase transformation to lithium titanate. As calculated, around 15% rutile nanoparticles more likely exist on the surface of anatase with the formation of a heterojunction structure, although isolated nanoparticles with sole rutile phase coexist. In addition to XRD analysis, TEM measurement shows that the Moiré fringes frequently present, which further manifests that some anatase particles are covered with rutile clusters or thin overlayers.
Highlights • Particulate matters (PMs) disrupted stratum corneum integrity by 2-fold. • The histology exhibited that PMs mildly damaged tight junctions. • The proteomic profiles showed that PMs ...upregulated Annexin A2 by >5-fold. • PMs increased the skin absorption of the extremely lipophilic tretinoin by 2.6-fold. • Oxybenzone and macromolecule absorption was not affected by PMs.
Porous scaffolds have long been regarded as optimal substitute for bone tissue repairing. In order to explore the influence of unit cell structure and inherent material characteristics on the porous ...scaffolds in terms of mechanical and biological performance, selective laser melting (SLM) technology was used to fabricate porous tantalum (Ta) and titanium alloy (Ti6Al4V) with diamond (Di) or rhombic dodecahedron (Do) unit cell structure. The mechanical strength of all the porous scaffolds could match that of trabecular bone, while the biological performance of each scaffold was diverse from each other. Moreover, the ILK/ERK1/2/Runx2 signaling pathway had been verified to be involved in the osteogenic differentiation of rat bone mesenchymal stem cells (rBMSCs) cultured on those porous scaffolds. Unit cell structure and material characteristics of the porous Ta and Ti6Al4V scaffolds can synergistically modulate this axis and further impact on the osteogenic effects. Our results hence illustrate that porous Ta scaffold with diamond unit cell structure possesses excellent osteogenic effects and moderate mechanical strength and porous Ti6Al4V scaffold with rhombic dodecahedron unit cell structure has the highest mechanical strength and moderate osteogenic effects. Both porous Ta and Ti6Al4V can be applied in different settings requiring either better biological performance or higher mechanical demand.
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•Porous tantalum and Ti6Al4V scaffolds are optimal substitutes for the restoration of trabecular bone defects.•Porous tantalum with diamond unit cell structure has satisfactory osteogenic effects.•Porous Ti6Al4V with rhombic dodecahedron unit cell structure possess fine mechanical strength.
Acute pancreatitis (AP) is an inflammatory disease mediated by damage to acinar cells and pancreatic inflammation. In patients with AP, subsequent systemic inflammatory responses and multiple organs ...dysfunction commonly occur. Interactions between cytokines and oxidative stress greatly contribute to the amplification of uncontrolled inflammatory responses. Molecular hydrogen (H2) is a potent free radical scavenger that not only ameliorates oxidative stress but also lowers cytokine levels. The aim of the present study was to investigate the protective effects of H2 gas on AP both in vitro and in vivo. For the in vitro assessment, AR42J cells were treated with cerulein and then incubated in H2-rich or normal medium for 24 h, and for the in vivo experiment, AP was induced through a retrograde infusion of 5% sodium taurocholate into the pancreatobiliary duct (0.1 mL/100 g body weight). Wistar rats were treated with inhaled air or 2% H2 gas and sacrificed 12 h following the induction of pancreatitis. Specimens were collected and processed to measure the amylase and lipase activity levels; the myeloperoxidase activity and production levels; the cytokine mRNA expression levels; the 8-hydroxydeoxyguanosine, malondialdehyde, and glutathione levels; and the cell survival rate. Histological examinations and immunohistochemical analyses were then conducted. The results revealed significant reductions in inflammation and oxidative stress both in vitro and in vivo. Furthermore, the beneficial effects of H2 gas were associated with reductions in AR42J cell and pancreatic tissue damage. In conclusion, our results suggest that H2 gas is capable of ameliorating damage to the pancreas and AR42J cells and that H2 exerts protective effects both in vitro and in vivo on subjects with AP. Thus, the results obtained indicate that this gas may represent a novel therapy agent in the management of AP.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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