High‐performance microwave absorbers with special features are desired to meet the requirements of more complex modern service environments, especially corrosive environments. Therefore, high‐efficiency microwave absorbers with corrosion resistance should be developed urgently. Herein, a 3D NiAl‐layered double hydroxide/graphene (NiAl‐LDH/G) composite synthesized by atomic‐layer‐deposition‐assisted in situ growth is presented as an anticorrosive microwave absorber. The content of NiAl‐LDH in the composite is optimized to achieve impedance matching. Furthermore, under the cooperative effects of the interface polarization loss, conduction loss, and 3D porous sandwich‐like structure, the optimal NiAl‐LDH/G shows excellent microwave absorption performance with a minimum reflection loss of −41.5 dB and a maximum effective absorption bandwidth of 4.4 GHz at a loading of only 7 wt% in epoxy. Remarkably, the encapsulation effect of NiAl‐LDH can restrain the galvanic corrosion owing to graphene. The epoxy coating with the NiAl‐LDH/G microwave absorber on carbon steel exhibits long‐term corrosion resistance, owing to the synergetic effect of the superior impermeability of graphene and the chloridion‐capture capacity of the NiAl‐LDH. The NiAl‐LDH/G composite is a promising anticorrosive microwave absorber, and the findings of this study may motivate the development of functional microwave absorbers that meet the demands of anticorrosive performance of coatings.
BACKGROUND:The treatment, prognosis, and outcomes of young lung cancer patients have not been fully explored. In addition, there is a pressing need to characterize this subgroup of patients, because there is a trend of increasing incidence in younger patients from Europe and Japan. METHODS: Consecutive, nonselected young patients (<45 years old) with pathologically diagnosed lung cancer treated at 175 qualified hospitals in the greater Shanghai area were included in this analysis. Incidence, prognostic factors, and treatment outcome of lung cancer patients from 2002 to 2006 were documented. A comparison with lung cancer patients of any age was also made. RESULTS: A total of 12,380 patients with nonsmall cell lung cancer were registered. Among them, 652 patients were between 15 and 45 years old. One-year, 3-year, and 5-year survival rates of lung cancer patients younger than 45 years were 49.87%, 26.68%, and 23.12%, respectively. TNM stage, treatment hospital (tertiary vs community hospital), sex, and cancer histology were confirmed as independent prognostic factors. Compared with lung cancer patients of any age in Shanghai, the percentage of adenocarcinoma in the young male subgroup was significantly higher (63.77% vs 43.19%, P < .001). Interestingly, median survival time of young lung cancer patients was similar with that of lung cancer patients of any age, but was significantly shorter than the median survival of middle-aged patients (45-60 years old). CONCLUSIONS: Median survival of the middle-aged group (45-60 years) was significantly longer than the young group (<45 years) and the old group (>60 years). Therefore, aggressive treatment modalities should be strongly considered for young lung cancer patients. Cancer 2010;116;3656-62.
Cytidine triphosphate synthase (CTPS), which comprises an ammonia ligase domain and a glutamine amidotransferase domain, catalyzes the final step of de novo CTP biosynthesis. The activity of CTPS is regulated by the binding of four nucleotides and glutamine. While glutamine serves as an ammonia donor for the ATP-dependent conversion of UTP to CTP, the fourth nucleotide GTP acts as an allosteric activator. Models have been proposed to explain the mechanisms of action at the active site of the ammonia ligase domain and the conformational changes derived by GTP binding. However, actual GTP/ATP/UTP binding modes and relevant conformational changes have not been revealed fully. Here, we report the discovery of binding modes of four nucleotides and a glutamine analog 6-diazo-5-oxo-L-norleucine in Drosophila CTPS by cryo–electron microscopy with near-atomic resolution. Interactions between GTP and surrounding residues indicate that GTP acts to coordinate reactions at both domains by directly blocking ammonia leakage and stabilizing the ammonia tunnel. Additionally, we observe the ATP-dependent UTP phosphorylation intermediate and determine interacting residues at the ammonia ligase. A noncanonical CTP binding at the ATP binding site suggests another layer of feedback inhibition. Our findings not only delineate the structure of CTPS in the presence of all substrates but also complete our understanding of the underlying mechanisms of the allosteric regulation and CTP synthesis.
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