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Biofilms are the chief culprits of most intractable infections and pose great threat to human health. Developing effective strategies to sweep away the detrimental microbe and stubborn biofilm still remains a challenge. Here, an ultrasound (US) activated microbomb is constructed by encapsulating perfluorohexane (PFH) and iron‐tannin modified calcium peroxide (CaO2‐TA‐Fe) in poly(lactide‐co‐glycolide) (PLGA) vesicles as the reactive oxygen species (ROS) generating reactors for dental biofilm elimination. Upon the US irradiation by ultrasonic toothbrush, the swiftly vaporized PFH can not only promptly explode the PLGA shell to facilitate the generation of H2O2 from CaO2, but also blast the tight biofilm for effective delivery of the lethal hydroxyl free radicals (•OH) caused by degradative Fe3+ from iron‐tannin network, thereby proceeding cascade catalysis eradication of biofilm. As a proof‐of‐concept, this study demonstrates the proposed synergetic paradigm that integrates the US‐triggered explosion with ROS‐induced sterilization for stubborn biofilm elimination, and is a promising tactic for the costly and prevalent caries prevention as well as the biofilm‐associated diseases treatments. [ABSTRACT FROM AUTHOR]

For practical lithium–sulfur batteries (LSBs), the high sulfur loading and lean‐electrolyte are necessary conditions to achieve the high energy density. However, such extreme conditions will cause serious battery performance fading, due to the uncontrolled deposition of Li2S and lithium dendrite growth. Herein, the tiny Co nanoparticles embedded N‐doped carbon@Co9S8 core–shell material (CoNC@Co9S8NC) is designed to address these challenges. The Co9S8NC‐shell effectively captures lithium polysulfides (LiPSs) and electrolyte, and suppresses the lithium dendrite growth. The CoNC‐core not only improves electronic conductivity, but also promotes Li+ diffusion as well as accelerates Li2S deposition/decomposition. Consequently, the cell with CoNC@Co9S8NC modified separator delivers a high specific capacity of 700 mAh g−1 with a low‐capacity decay rate of 0.035% per cycle at 1.0 C after 750 cycles under a sulfur loading of 3.2 mg cm−2 and a E/S ratio of 12 µL mg−1, and a high initial areal capacity of 9.6 mAh cm−2 under a high sulfur loading of 8.8 mg cm−2 and a low E/S ratio of 4.5 µL mg−1. Besides, the CoNC@Co9S8NC exhibits an ultralow overpotential fluctuation of 11 mV at a current density of 0.5 mA cm–2 after 1000 h during a continuous Li plating/striping process. [ABSTRACT FROM AUTHOR]

In karst regions, bedrock fissures are developed via karstification, which may cause belowground soil erosion (BSE). However, few studies have quantitatively assessed the effect of bedrock fissures on BSE because BSE measurement is difficult on karst hillslopes. The objective of this study was to investigate the differences in runoff and soil erosion at the surface and belowground on karst hillslopes with and without bedrock fissures (hereafter called HS1 and HS2, respectively) under different rainfall intensities (50, 75, and 100 mm hr−1). The slope gradient was 5°. In the rainfall process, surface runoff (SR), subsurface runoff (SBR), soil–rock interface flow (SRIF), and underground fissure flow (UFF) data were collected on HS1 and HS2. The results showed that the SR coefficients of HS1 and HS2 were negligible (less than 1%) under rainfall intensities of 50 and 75 mm hr−1, and UFF (56%–57%) of HS1 and SRIF (40%–44%) of HS2 dominated the runoff pattern. Under a rainfall intensity of 100 mm hr−1, the SR coefficient increased to approximately 30% under the two treatments, and the coefficients of UFF of HS1 and SRIF of HS2 decreased to 29% and 24%, respectively. Compared to HS2, UFF of HS1 increased by 18%–39%. The SBR coefficient was lower than 10% for all rainfall events. Because SR and SBR were low under rainfall intensities of 50 and 75 mm hr−1, the soil loss was dominated by UFF (99%–100% of the total sediment) of HS1 and by SRIF (86%–97% of the total sediment) of HS2. Under the 100 mm hr−1 rainfall intensity, almost all sediment was lost via SR under the two treatments, and the sediment loss of HS2 was 33% higher than that of HS1. Our results indicated that bedrock fissures caused more underground rainwater leakage at the SRI and further decreased surface soil erosion on karst hillslopes. [ABSTRACT FROM AUTHOR]

Epitaxial Cd2SnO4 films were fabricated on MgO(00l) single crystalline substrates by pulsed laser deposition technique at various substrate temperatures and growth oxygen pressures. The microstructure, transport, and optical properties of the films were studied in detail. High‐resolution X‐ray diffraction and high‐resolution transmission electron microscopy results demonstrate that all the Cd2SnO4 films are grown epitaxially on MgO(00l) substrates. Atomic force microscope images indicate that the films have smooth surface morphologies. Hall‐effect measurements reveal that the epitaxial film grown at 680°C and 40 Pa presents the minimum resistivity value of 0.61 mΩcm and maximal Hall mobility of 32.87 cm2 V−1 s−1. The metal–semiconductor transitions of Cd2SnO4 films were observed and explained by competitive effects of two conductive mechanisms. The optical transmittance of the Cd2SnO4 films is higher than 75% in the visible and near‐infrared range, and the optical bandgap was determined to be about 3.09 eV for the film grown at optimal condition. The band structure and density of states of the Cd2SnO4 were calculated by the density functional theory. [ABSTRACT FROM AUTHOR]

Rainwater interception by leaf litter is an important part of forest hydrological processes. The objective of this study was to investigate the interception storage capacity (ISC) of woodland leaf litter for three leaf distribution patterns, one flow path, two flow paths, and three flow paths, manually simulated via one‐by‐one leaf connection in the top leaf litter layer. A random pattern served as the control. Three different slopes (0°, 5° and 25°, representing flat, gentle and steep slopes, respectively) and two contrasting leaf litters (needle‐leaf litter, represented by P. massoniana leaves, and broad‐leaf litter, represented by C. camphora leaves) with a biomass of 0.5 kg/m2 per unit area were applied, at a rainfall intensity of 50 mm/h. Results suggested that leaf distribution pattern greatly impacts litter drainage and hence affects leaf litter ISC. The delaying capacity of litter drainage initiation and ISC of broad‐leaf litter were higher than those of needle‐leaf litter under the same slope conditions. The maximum ISC (Cmax) and minimum ISC (Cmin) of leaf litter at flat and gentle slopes were higher than those at steep slope. Cmin of the broad‐leaf litter was two times higher than that of needle‐leaf litter on average. When raindrops reached the litter layer, some were temporarily intercepted by the top litter layer while others infiltrated leaf litter sublayer along leaf edges, and in the process, some rainwater flowed through litter layer and contributed to lateral litter drainage along the potential flow path formed by leaves. The lateral litter drainage of broad‐leaf litter was higher than that of needle‐leaf litter, and the partitioning of rainwater into lateral litter drainage increased with increases in slope. The difference in leaf litter Cmax among different slopes and leaf shapes decreased with flow path increasing. Therefore, leaf distribution pattern notably impact leaf litter ISC, which is similar to leaf shape and slope impacts. On inclined slopes, avoiding leaf accumulation to form flow path is helpful for improving ISC. [ABSTRACT FROM AUTHOR]

Melatonin functions as an endogenous protective molecule in multiple vascular diseases, whereas its effects on thoracic aortic aneurysm and dissection (TAAD) and underlying mechanisms have not been reported. In this study, TAAD mouse model was successfully induced by β‐aminopropionitrile fumarate (BAPN). We found that melatonin treatment remarkably prevented the deterioration of TAAD, evidenced by decreased incidence, ameliorated aneurysmal dilation and vascular stiffness, improved aortic morphology, and inhibited elastin degradation, macrophage infiltration, and matrix metalloproteinase expression. Moreover, melatonin blunted oxidative stress damage and vascular smooth muscle cell (VSMC) loss. Notably, BAPN induced a decrease in SIRT1 expression and activity of mouse aorta, whereas melatonin treatment reversed it. Further mechanistic study demonstrated that blocking SIRT1 signaling partially inhibited these beneficial effects of melatonin on TAAD. Additionally, the melatonin receptor was involved in this phenomenon. Our study is the first to report that melatonin exerts therapeutic effects against TAAD by reducing oxidative stress and VSMC loss via activation of SIRT1 signaling in a receptor‐dependent manner, thus suggesting a novel therapeutic strategy for TAAD. [ABSTRACT FROM AUTHOR]

Melatonin, a circadian molecule secreted by the pineal gland, confers a protective role against cardiac hypertrophy induced by hyperthyroidism, chronic hypoxia, and isoproterenol. However, its role against pressure overload-induced cardiac hypertrophy and the underlying mechanisms remains elusive. In this study, we investigated the pharmacological effects of melatonin on pathological cardiac hypertrophy induced by transverse aortic constriction ( TAC). Male C57 BL/6 mice underwent TAC or sham surgery at day 0 and were then treated with melatonin (20 mg/kg/day, via drinking water) for 4 or 8 weeks. The 8-week survival rate following TAC surgery was significantly increased by melatonin. Melatonin treatment for 8 weeks markedly ameliorated cardiac hypertrophy. Compared with the TAC group, melatonin treatment for both 4 and 8 weeks reduced pulmonary congestion, upregulated the expression level of α-myosin heavy chain, downregulated the expression level of β-myosin heavy chain and atrial natriuretic peptide, and attenuated the degree of cardiac fibrosis. In addition, melatonin treatment slowed the deterioration of cardiac contractile function caused by pressure overload. These effects of melatonin were accompanied by a significant upregulation in the expression of peroxisome proliferator-activated receptor-gamma co-activator-1 beta ( PGC-1β) and the inhibition of oxidative stress. In vitro studies showed that melatonin also protects against angiotensin II-induced cardiomyocyte hypertrophy and oxidative stress, which were largely abolished by knocking down the expression of PGC-1β using small interfering RNA. In summary, our results demonstrate that melatonin protects against pathological cardiac hypertrophy induced by pressure overload through activating PGC-1β. [ABSTRACT FROM AUTHOR]

A kind of semiaromatic polyamide, poly(dodecamethylene terephthalamide) (PA12T) was synthesized via a polycondensation reaction of terephthalic acid and 1,12-dodecanediamine. The structure of prepared PA12T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (1H-NMR), and elemental analysis. The mechanical properties of PA12T were also studied. The thermal behavior of PA12T was determined by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. Pyrolysis products and thermal decomposition mechanism of PA12T were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Melting temperature ( T m), glass transition temperature ( T g), and decomposition temperature ( T d) of PA12T are 310°C, 144°C, and 429°C, respectively. The Py-GC/MS results showed that the pyrolysis products were mainly composed of 32 kinds of compounds, such as benzonitrile, 1,4-benzenedicarbonitrile, N-methylbenzamide, N-hexylbenzamide, and aromatic compounds. The major pyrolysis mechanisms were β-CH hydrogen transfer process, main-chain random scission, and hydrolytic decomposition. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011. [ABSTRACT FROM AUTHOR]