[1] The existence of gas-phase ammonia (NH 3 ) in the atmosphere and its interaction with other trace chemical species could have a substantial impact on tropospheric chemistry and global climate change. China is a large agricultural country with an enormous animal population, tremendous nitrogen fertilizer consumption and, consequently, a large emission of NH 3 . Despite the importance of NH 3 in the global nitrogen (N) cycle, considerable inaccuracies and uncertainty exist regarding its emission in China. In this study, a comprehensive NH 3 emission inventory was compiled for China on a 1 km  1 km grid, which is suitable for input to atmospheric models. We attempted to estimate NH 3 emissions accurately by taking into consideration as many native experiment results as possible and parameterizing the emission factors (EFs) by the ambient temperature, soil acidity and other factors. The total NH 3 emission in China was approximately 9.8 Tg in 2006. The emission sources considered included livestock excreta (5.3 Tg), fertilizer application (3.2 Tg), agricultural soil (0.2 Tg), nitrogen-fixing plants (0.05 Tg), crop residue compost (0.3 Tg), biomass burning (0.1 Tg), urine from rural populations (0.2 Tg), chemical industry (0.2 Tg), waste disposal (0.1 Tg) and traffic (0.1 Tg). The regions with the highest emission rates are located in Central and Southwest China. Seasonally, the peak ammonia emissions occur in spring and summer.
Hypoxia is a common phenomenon among most solid tumors that significantly influences tumor response toward chemo-and radiotherapy. Understanding the distribution and extent of tumor hypoxia in patients will be very important to provide personalized therapies in the clinic. Without sufficient vessels, however, traditional contrast agents for clinical imaging techniques will have difficulty in accumulating in the hypoxic region of solid tumors, thus challenging the detection of hypoxia in vivo. To overcome this problem, herein we develop a novel hypoxia imaging probe, consisting of a hypoxia-triggered self-assembling ultrasmall iron oxide (UIO) nanoparticle and assembly-responding fluorescence dyes (NBD), to provide dual-mode imaging in vivo. In this strategy, we have employed nitroimidazole derivatives as the hypoxia-sensitive moiety to construct intermolecular cross-linking of UIO nanoparticles under hypoxia, which irreversibly form larger nanoparticle assemblies. The hypoxia-triggered performance of UIO self-assembly not only amplifies its T 2 -weighted MRI signal but also promotes the fluorescence intensity of NBD through its emerging hydrophobic environment incorporated into self-assemblies. In vivo results further confirm that our hypoxic imaging probe can display a prompt MRI signal for the tumor interior region, and its signal enhancement performs a long-term effective feature and gradually reaches 3.69 times amplification. Simultaneously, this probe also exhibits obvious green fluorescence in the hypoxic region of tumor sections. Accordingly, we also have developed a MRI difference value method to visualize the 3D distribution and describe the extent of the hypoxic tumor region within the whole bodies of mice. Due to its notable efficiency of penetration and accumulation inside a hypoxic tumor, our hypoxia imaging probe could also be considered as a potential candidate as a versatile platform for hypoxiatargeted drug delivery, and meanwhile its hypoxia-related therapeutic efficacy can be monitored.
ScopeA high salt (HS) diet is detrimental to cognitive function, in addition to having a role in cardiovascular disorders. However, the method by which an HS diet impairs cognitive functions such as learning and memory remains open.Methods and resultsIn this study, we found that mice on a 7 week HS diet demonstrated disturbed short‐term memory in an object‐place recognition task, and both 4 week and 7 week HS treatments impaired long‐term memory, as evidenced in a fear conditioning test. Mechanistically, the HS diet inhibited memory‐related long‐term potentiation (LTP) in the hippocampus, while also increasing the levels of reactive oxygen species (ROS) in hippocampal cells and downregulating the expression of synapsin I, synaptophysin, and brain‐derived neurotrophic factor in specific encephalic region.ConclusionThis suggests that oxidative stress or synaptic protein/neurotrophin deregulation was involved in the HS diet‐induced memory impairment. Thus, the present study provides novel insights into the mechanisms of memory impairment caused by excessive dietary salt, and underlined the importance of controlling to salt absorb quantity.
High-risk HPV is clearly associated with cervical cancer. HPV integration has been confirmed to promote carcinogenesis in the previous studies. In our study, a total of 285 DNA breakpoints and 287 RNA breakpoints were collected. We analyzed the characteristic of HPV integration in the DNA and RNA samples. The results revealed that the patterns of HPV integration in RNA and DNA samples differ significantly. FHIT, KLF5, and LINC00392 were the hotspot genes integrated by HPV in the DNA samples. RAD51B, CASC8, CASC21, ERBB2, TP63, TEX41, RAP2B, and MYC were the hotspot genes integrated by HPV in RNA samples. Breakpoints of DNA samples were significantly prone to the region of INTRON (P < 0.01, Chi-squared test), whereas in the RNA samples, the breakpoints were prone to EXON. Pathway analysis had revealed that the breakpoints of RNA samples were enriched in the pathways of transcriptional misregulation in cancer, cancer pathway, and pathway of adherens junction. Breakpoints of DNA samples were enriched in the pathway of cholinergic synapse. In summary, our data helped to gain insights into the HPV integration sites in DNA and RNA samples of cervical cancer. It had provided theoretical basis for understanding the mechanism of tumorigenesis from the perspective of HPV integration in the HPV-associated cervical cancers.
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