Gastric cancer-derived exosomes facilitate pulmonary metastasis by activating ERK-mediated immunosuppressive macrophage polarization.

Gastric cancer (GC) with pulmonary metastasis is one of the deadliest diseases in the world; however, the underlying pathological mechanisms and potential therapeutic targets remain to be elucidated. As exosomes play indispensable roles in the formation of premetastatic niches (PMN) and cancer metastasis. Therefore, investigating the underlying mechanisms of exosome-mediated pulmonary metastasis of GC may shed new light on identifying novel therapeutic targets for GC treatment. GC-derived exosomes were isolated from the conditioned medium of mouse forestomach carcinoma (MFC) cell line. The effects of MFC-derived exosomes on pulmonary macrophage polarization were analyzed by reverse- transcription polymerase chain reaction and flow cytometry. Expression of PD-L1 and other proteins was evaluated by Western blot. Exosomal microRNAs (miRNAs) were analyzed by microarray. GC-derived exosomes (GC-exo) accumulated in high numbers in the lungs and were ingested by macrophages. The extracellular-signal-regulated kinase (ERK) signaling pathway was activated by GC-exo, inducing macrophage immunosuppressive-phenotype differentiation and increased PD-L1 expression. miRNA-sequencing identified 130 enriched miRNAs in GC-exo. Among the enriched miRNAs, miR-92a-3p plays a major role in activating ERK signaling via inhibition of PTEN expression. In addition, inhibiting ERK signaling with PD98059 significantly reduced the expression of PD-L1 in macrophages and, therefore, reversed the immunosuppressive PMN and inhibited the colonization of GC cells in the lungs. This study identified a novel mechanism of GC-exo mediated PD-L1 expression in lung macrophages that facilitates lung PMN formation and GC pulmonary metastasis, which also provided a potential therapeutic target for GC with pulmonary metastasis treatment.

Mass Spectrometry-Imaging Analysis of Active Ingredients in the Leaves of Taxus cuspidata.

BACKGROUND: Taxus cuspidata is an endangered evergreen conifer mainly found in Northeast Asia. In addition to the well-known taxanes, several active ingredients were detected in the leaves of T. cuspidata. However, the precise spatial distribution of active ingredients in the leaves of T. cuspidata is largely unknown. RESULTS: in the present study, timsTOF flex MALDI-2 analysis was used to uncover the accumulation pattern of active ingredients in T. cuspidata leaves. In total, 3084 ion features were obtained, of which 944 were annotated according to the mass spectrometry database. The principal component analysis separated all of the detected metabolites into four typical leaf tissues: mesophyll cells, upper epidermis, lower epidermis, and vascular bundle cells. Imaging analysis identified several leaf tissues that specifically accumulated active ingredients, providing theoretical support for studying the regulation mechanism of compound biosynthesis. Furthermore, the relative accumulation levels of each identified compound were analyzed. Two flavonoid compounds, ligustroflavone and Morin, were identified with high content through quantitative analysis of the ion intensity. CONCLUSIONS: our data provides fundamental information for the protective utilization of T. cuspidata.

Anthropogenic warming is a key climate indicator of rising urban fire activity in China.

China, one of the most populous countries in the world, has suffered the highest number of natural disaster-related deaths from fire. On local scales, the main causes of urban fires are anthropogenic in nature. Yet, on regional to national scales, little is known about the indicators of large-scale co-varying urban fire activity in China. Here, we present the China Fire History Atlas (CFHA), which is based on 19 947 documentary records and represents fires in urban areas of China over the twentieth century (1901-1994). We found that temperature variability is a key indicator of urban fire activity in China, with warmer temperatures being correlated with more urban fires, and that this fire-temperature relationship is seasonally and regionally explicit. In the early twentieth century, however, the fire-temperature relationship was overruled by war-related fires in large urban areas. We further used the fire-temperature relationship and multiple emissions scenarios to project fire activity across China into the twenty-first century. Our projections show a distinct increase in future urban fire activity and fire-related economic loss. Our findings provide insights into fire-climate relationships in China for densely-populated areas and on policy-relevant time scales and they contribute spatial coverage to efforts to improve global fire models.

Effects of high air temperature, drought, and both combinations on maize: A case study.

High air temperature (HAT) and natural soil drought (NSD) have seriously affected crop yield and frequently take place in a HAT-NSD combination. Maize (Zea mays) is an important crop, thermophilic but not heat tolerant. In this study, HAT, NSD, and HAT-NSD effects on maize inbred line Huangzao4 -were characterized. Main findings were as follows: H2O2 and O- accumulated much more in immature young leaves than in mature old leaves under the stresses. Lateral roots were highly distributed near the upper pot mix layers under HAT and near root tips under HAT-NSD. Saccharide accumulated mainly in stressed root caps (RC) and formed a highly accumulated saccharide band at the boundary between RC and meristematic zone. Lignin deposition was in stressed roots under NSD and HAT-NSD. Chloroplasts increased in number and formed a high-density ring around leaf vascular bundles (VB) under HAT and HAT-NSD, and sparsely scattered in the peripheral area of VBs under NSD. The RC cells containing starch granules were most under NAD-HAT but least under HAT. Under NSD and HAT-NSD followed by re-watering, anther number per tassel spikelet reduced to 3. These results provide multiple clues for further distinguishing molecular mechanisms for maize to tolerate these stresses.

Synergistic effect of a triethanolamine-modified carbon-based layered double hydroxide for efficient removal of nitrate from micro-polluted water.

Owing to the ubiquitous existence and low concentrations of detrimental nitrogen pollutants in micro-polluted water, simple adsorption-oriented approaches are becoming increasingly appealing for the effective removal of NO3- from wastewater. Triethanolamine (TDA) modified carbon-based layered double hydroxide (LDH) composites (TDA@LDH/CS) were synthesized by a supersaturated co-precipitation method for efficient NO3- adsorption. The characterization results showed that TDA@LDH/CS, formed by the stacking of irregular nanosheets and lamellar aggregates, has a mesoporous structure and a specific surface area of 67.15 m2 g-1. The Langmuir and pseudo-second-order kinetic models were well fitted with the adsorption of NO3- by TDA@LDH/CS, with the maximum adsorption capacity reaching 14.45 mg g-1, and the adsorption process was consistent with the spontaneous exothermic entropy increasement. Furthermore, the synergistic adsorption mechanism of NO3- by the TDA-modified materials was proposed using XPS analysis, which indicated that TDA modification greatly enriched the surface of TDA@LDH/CS with tertiary amine groups (R3N) and hydroxyl groups (-OH), providing more adsorption sites and active sites. After five cycles, the NO3- removal rate could still reach 64.2%, which exhibited its high potential to be utilized as an adsorbent for the removal of nitrogen pollutants from micro-polluted water.

MnO Nanoparticles Supported by Carbonized Cotton Fiber Foil as a Free-Standing Anode for High-Performance Lithium Ion Batteries.

A three-dimensional (3D) network structure composite of MnO nanoparticles (NPs) and carbonized cotton fiber foil (CCFF) is introduced as an anode material free of binders and conductive additives for Li-ion batteries (LIBs). CCFF with its closely linked networks provides a stable framework for metal oxides and improves the electrical conductivity of the composite. MnO NPs are evenly distributed on the surface of CCFF and concurrently embedded in the carbon matrix through simply annealing the MnO precursor (MnO-P)/cotton fiber foil (CFF) composite. When the obtained MnO/CCFF composite is used as a self-supporting anode in LIBs, the electrode displays stable cycling performance and superior rate capability, which can be attributed to the close contact between the well-dispersed MnO NPs and the interlaced carbon fibers. The rational design using CCFF as the current collector in batteries and the carbon substrate to support the active materials could greatly enhance the electronic/ionic transmission channels and effectively relieve the volume expansion of MnO during the electrochemical process. In addition, the self-standing MnO/CCFF electrode may serve as a template for the design of other metal oxide anode materials supported by carbonized cotton fiber foil for high-performance LIBs.

Template-free synthesis of nanoparticle-built MgO and Zn-doped MgO hollow microspheres with superior performance for Congo red adsorption from water.

Nanoparticle-built MgO hollow microspheres were synthesized through a template-free hydrothermal route using citrate as a structural director. Zn was introduced into MgO to improve the surface charge. Pure MgO and Zn-doped MgO samples were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and a zeta-potential analyzer. The as-prepared microspheres showed outstanding performance for the removal of Congo red (CR, anionic dye) from solutions. The maximum adsorption capacities of pure MgO and Zn-doped MgO samples were 3022.02 and 2953.39 mg g-1, respectively. The Zn-loaded sample only required 45 min to reach equilibrium, which was much shorter than that of pure MgO sample (120 min) and most previously reported adsorbents. The high adsorption capacity and efficiency for CR removal resulted from the samples' unique porous structures and positive surface charges at pH 7. The adsorption process followed Langmuir isotherm and pseudo-second-order model. Regeneration assessment was conducted by a method of calcining for four times, and the observed steady adsorption efficiency indicated a bright prospect for the two samples in wastewater treatment.

Synthesis of core-shell SiO2@MgO with flower like morphology for removal of crystal violet in water.

In this study, we report a facile and effective route to synthesize core-shell SiO2@MgO with flower like morphology, which the shell is assembled by magnesium oxide nanosheets. The SiO2@MgO composite (SMC) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), X-ray fluorescence (XRF) and N2 adsorption-desorption techniques. The sample showed excellent performance for the removal of crystal violet due to its high specific surface area and porous structures. Adsorption data fitted better with Langmuir isotherm and the maximum adsorption capacity was 2244.85 mg g(-1). The kinetic data was better described by pseudo-second order model and thermodynamic studies showed that adsorption process was spontaneous and endothermic. The adsorbent also showed very good reproducibility and reusability for the successive five cycles, indicating a promising potential material for environmental remediation.