In this study, we investigated the impact of cigarette smoke on tumor immune surveillance and its consequences to lung tumor burden in a murine lung metastasis model. Cigarette smoke exposure ...significantly increased the numbers of lung metastases following B16-MO5 melanoma challenge. This effect was reversible; we observed significantly fewer tumor nodules following smoking cessation. Using RAG2(-/-) and RAG2(-/-)gamma(c)(-/-) mice, we provide strong evidence that increased tumor incidence was NK cell dependent. Furthermore, we show that cigarette smoke suppressed NK activation and attenuated NK CTL activity, without apparent effect on activating or inhibitory receptor expression. Finally, activation of NK cells through bone marrow-derived dendritic cells conferred protection against lung metastases in smoke-exposed mice; however, protection was not as efficacious as in sham-exposed mice. To our knowledge, this is the first experimental evidence showing that cigarette smoke impairs NK cell-dependent tumor immune surveillance and that altered immunity is associated with increased tumor burden. Our findings suggest that altered innate immunity may contribute to the increased risk of cancer in smokers.
•Ethanol precipitation for natural polysaccharide preparation was critically evaluated.•Ethanol concentration was emphatically concerned.•Varied ethanol concentrations could significantly affect the ...precipitated results.•Chemical diversity of polysaccharides is the decisive factor in ethanol precipitation.•Ethanol precipitation for natural polysaccharide should be individually optimized.
Ethanol precipitation is one of the most widely used methods for preparing natural polysaccharides, in which ethanol concentration significantly affects the precipitate yield, however, is usually set at 70–80%. Whether the standardization of ethanol concentration is appropriate has not been investigated. In the present study, the precipitation yields produced in varied ethanol concentrations (10–90%) were qualitatively and quantitatively evaluated by HPGPC (high-performance gel-permeation chromatography), using two series of standard glucans, namely dextrans and pullulans, as reference samples, and then eight natural samples. The results indicated that the response of a polysaccharide's chemical structure, with diversity in structural features and molecular sizes, to ethanol concentration is the decisive factor in precipitation of these glucans. Polysaccharides with different structural features, even though they have similar molecular weights, exhibit significantly different precipitation behaviors. For a specific glucan, the lower its molecular size, the higher the ethanol concentration needed for complete precipitation. The precipitate yield varied from 10% to 100% in 80% ethanol as the molecular size increased from 1kDa to 270kDa. This paper aims to draw scientists’ attention to the fact that, in extracting natural polysaccharides by ethanol precipitation, the ethanol concentration must be individually optimized for each type of material.
We investigate laser bonding of Zr41Ti14Cu12Ni10Be23 bulk metallic glass (BMG) using experiments and finite element simulation. The specimen plates with 5 × 30 × 1.3 mm3 are welded together ...successfully and the welded joint maintains fully amorphous under the welding parameters of 1.3 kW and 7 m min−1. To examine in detail the thermal stability of the welded joint, we employ the SYSWELD software to simulate the distribution of temperature field and thermal cycle curves. The simulation results are consistent with the laser welding experiments, and there is no intersection point between the thermal cycle curves and time–temperature‐transformation diagram, indicating that the joint retains amorphous structure.
The Zr41Ti14Cu12Ni10Be23 bulk metallic glass (BMG) is welded using laser bonding. To overcome the limitation in probing the temperature field and optimize the welding parameters of BMG bonding, the finite element method is used to simulate temperature field and calculate thermal cycle. The dynamic temperature contours and the thermal cycle curves describe the thermal interaction during laser welding.
A number of schemes have been proposed for providing quality-of-service (QoS) differentiation in optical burst-switched (OBS) networks. Most existing schemes are based on a relative QoS model in ...which the service requirements for a given class of traffic are defined relative to the service requirements of another class of traffic. In this paper, we propose an absolute QoS model in OBS networks which ensures that the loss probability of the guaranteed traffic does not exceed a certain value. We describe two mechanisms for providing loss guarantees at OBS core nodes: an early dropping mechanism, which probabilistically drops the nonguaranteed traffic, and a wavelength grouping mechanism, which provisions necessary wavelengths for the guaranteed traffic. It is shown that integrating these two mechanisms outperforms the stand-alone schemes in providing loss guarantees, as well as reducing the loss experienced by the nonguaranteed traffic. We also discuss admission control and resource provisioning for OBS networks, and propose a path clustering technique to further improve the network-wide loss performance. We develop analytical loss models for the proposed schemes and verify the results by simulation.
Ammonia is a neurotoxin that can lead to significant and permanent neurological impairment. The accumulation of ammonia in the blood of patients with liver failure can cause life-threatening hepatic ...encephalopathy. However, until now, there has been a lack of efficient, safe, and specific adsorbents to remove ammonia from the blood of patients with liver failure. In this study, chitin/zeolite composite nanofibrous microspheres (CZ) were prepared and evaluated as safe, efficient, and specific blood ammonia sorbents to remove ammonia from hyperammonemia plasma for the treatment of hyperammonemia. The CZ microspheres were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, physical adsorption of N2, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. CZ consists of intertwined nanofibrous network microspheres constructed from chitin nanofibers and embedded zeolite. In the in vitro adsorption experiment, CZ exhibited rapid and good affinity for ammonia in both aqueous solution and hyperammonemia plasma. The adsorption capacity of CZ2 in aqueous solution was 17.673 mg/g, which is similar to that of zeolite. The level of blood ammonia in the hyperammonemia plasma decreased from 650 to 386 μmol/L after adsorption by CZ2. In addition, CZ has been demonstrated to have good compatibility with cells and blood components (such as erythrocytes, clotting factors, and proteins), exhibiting good biocompatibility and blood compatibility. All these meet the necessary requirements for the clinical use of blood ammonia adsorbents for blood purification. Therefore, CZ has potential applications in the ammonia-induced treatment of complications.
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•A blood compatible and efficient blood ammonia adsorbent of CZ based on chitin and zeolite was prepared.•CZ exhibited nanofibrous network microspheres constructed with twisted chitin nanofibers and embedded zeolite.•CZ possesses prominent affinity of blood ammonia, good biocompatibility and blood compatibility.•CZ is a safe, efficient and specific blood ammonia adsorbent for treatment of hyperammonemia.
We previously found that sulfur fumigation, a commonly used controversial method for the post-harvest handling of ginger, induces the generation of a compound in ginger, which was speculated to be a ...sulfur-containing derivative of 6-shogaol based on its mass data. However, the chemical and biological properties of the compound remain unknown. As a follow-up study, here we report the chemical structure, systemic exposure, and anticancer activity of the compound. Chromatographic separation, nuclear magnetic resonance analysis, and chemical synthesis structurally elucidated the compound as 6-gingesulfonic acid. Pharmacokinetics in rats found that 6-gingesulfonic acid was more slowly absorbed and eliminated, with more prototypes existing in the blood than 6-shogaol. Metabolism profiling indicated that the two compounds produced qualitatively and quantitatively different metabolites. It was further found that 6-gingesulfonic acid exerted significantly weaker antiproliferative activity on tumor cells than 6-shogaol. The data provide chemical and biological evidence that sulfur fumigation may impair the healthcare functions of ginger.
A new visual model was used to study the failure mechanism and earth pressure of cohesionless narrow backfill installed behind a rigid retaining wall. The experimental system can simulate the ...different displacement modes of the retaining wall, inclinations of the retaining wall and widths of the backfill. Using a HD camera, displacement transducers and earth pressure cells, the deformation of the backfill, displacement of the retaining wall and earth pressure on the wall were recorded. Image data were post-processed using geo-particle image velocimetry. The shear strain contours and displacement vector diagrams of the soil were obtained. The test results showed that under the translation mode of the retaining wall, a sliding surface develops as a reflection between the walls to reach the ground. As the backfill width decreases, the number of reflective sliding surfaces increases. The active earth pressure on the wall is less than that obtained from calculations performed using classical theories and has a nonlinear distribution. The number of reflective sliding surfaces can be reduced by increasing the retaining wall inclination. When the retaining wall was under a rotation displacement mode, the backfill exhibited progressive failure, and no reflective sliding surface was produced. The tests help to understand the special failure mechanism and earth pressure distribution of narrow backfills and provide a basis for theoretical research.
The shuttle behavior of soluble lithium polysulfides (LiPSs) and sluggish electrochemical conversion from LiPSs to Li2S lead to poor cycling performance, which is the major problem hindering the ...practical applications of lithium-sulfur (Li-S) batteries. Herein, we developed a one-pot carbothermal reduction method to synthesize new CoO nanoparticles decorated Co9S8 (Co9S8/CoO) heterostructures with well-defined interfaces, in which CoO shows strong adsorption function and Co9S8 has significant electrocatalysis function. The Co9S8/CoO heterostructures with rationally structural design can not only improve the chemical capturing between CoO and LiPSs but also facilitate the electrocatalytic activity of Co9S8 involving the reaction from soluable LiPSs to insoluble Li2S2 and subsequent solid-solid reaction from Li2S2 to Li2S. The synergistic adsorption-electrocatalysis function is verified by both theoretical calculations and electrochemical characterizations. The Li-S cell with the Co9S8/CoO-Graphene coated separator exhibits a coulombic efficiency of approximately 100% and delivers a specific capacity of 925 mA h g−1 with a fade rate of 0.049% per cycle over 1000 cycles under a high S loading (2.5 mg cm−2). This work provides an emerging view on the design of heterostructures with synergistic adsorption and electrocatalysis function for application in Li-S batteries and catalysis fields.
The Co9S8/CoO heterostructures with rationally designed structure can capture more LiPS molecules and these LiPS molecules completely convert to Li2S on the interfaces due to the synergistic absorption-electrocatalysis function. The cell employing the Co9S8/CoO-G coated separator delivers a specific capacity of 925 mA h g−1 after several cycles’ activation with a fade rate of 0.049% per cycle over 1000 cycles with a high S loading. Display omitted
•A new synthetic route to obtain the CoO nanoparticles decorated Co9S8 heterostructures.•The heterostructures show synergistic absorption-electrocatalysis behavior for LiPSs.•The heterostructures show selective electrocatalysis of Li2S2 to Li2S.
Fluidic memristor devices have received tremendous attention for smooth resistance switching in artificial synapses due to the ion migration, concentration polarization, and redox reactions ...mechanism. Here we provide a novel method of preparing microfluidic memristor with superior stability, robustness, and ultralow cost. The structure of the two-terminal memristor device is Cu/MMImCl: H2O/Cu, C5H9N2Cl. The ionic liquid of 1,3-dimethylimidazole chloride salt was used as representative IL to display resistive memory properties in a cylindrical microchannel of a capillary. The fabricated device shows hysteretic and bipolar I–V characteristics of memristor, which can respond to external stimuli, e.g., space length between two electrodes and applied voltage. Meanwhile, this artificial synapse can mimic synaptic plasticity under various pulse stimuli stably and repeatedly, which results in temporary memory behavior. Such device exhibits great potential value in the area of neuromorphic artificial synapses and memory states.
Abstract Sarcandra glabra (Chinese name, Zhongjiefeng) is an important herb widely used in traditional Chinese medicine. Lycopene has been shown to be a powerful antioxidant. This study aims to test ...the hypothesis that Sarcandra glabra combined with lycopene protect rats from lipopolysaccharide (LPS) induced acute lung injury (ALI). Metabolomics approach combined with pathological inspection, serum biochemistry examination, enzyme-linked immunosorbent assay and western blotting were used to explore the protective effects of Sarcandra glabra and lycopene on LPS-induced ALI, and to elucidate the underlying mechanisms. Results showed that Sarcandra glabra and lycopene could significantly ameliorate LPS-induced histopathological injuries, improve the anti-oxidative activities of rats, decrease the levels of TNF-α and IL-6, suppress the activations of MAPK and transcription factor NF-κB and reverse the disturbed metabolism towards the normal status. Taken together, this integrated study revealed that Sarcandra glabra combined with lycopene had great potential in protecting rats from LPS-induced ALI, which would be helpful to guide the clinical medication.
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