The incorporation of a trifluoromethyl (CF3) group into organic compounds is of great importance in pharmaceutical, agricultural, and materials science. Trifluoromethylation based on radical ...intermediates, as a valuable alternative transformation using the inexpensive and stable solid sodium trifluoromethanesulfinate (CF3SO2Na; Langlois’ reagent), has attracted much attention and has become a hot research field. This review examines recent advances in radical trifluoromethylation reactions with CF3SO2Na as CF3 source.
Recent advances in trifluoromethylation or difluoroalkylation reactions by use of difluorinated phosphonium salts are summarized. In the presence of base, water, photocatalyst, fluoride or under the ...heating conditions, the difluorinated phosphonium salts can produce difluorocarbene, the CF2H radical or the trifluoromethyl anion, which are major intermediates for the difluoroalkylation or trifluoromethylation reaction and give moderate to excellent yields of the desired products in most cases.
Perovskite light-emitting diodes (PeLEDs) have showed significant progress in recent years; the external quantum efficiency (EQE) of electroluminescence in green and red regions has exceeded 20%, but ...the efficiency in blue lags far behind. Here, a large cation CH
CH
NH
is added in PEA
(CsPbBr
)
PbBr
perovskite to decrease the Pb-Br orbit coupling and increase the bandgap for blue emission. X-ray diffraction and nuclear magnetic resonance results confirmed that the EA has successfully replaced Cs
cations to form PEA
(Cs
EA
PbBr
)
PbBr
. This method modulates the photoluminescence from the green region (508 nm) into blue (466 nm), and over 70% photoluminescence quantum yield in blue is obtained. In addition, the emission spectra is stable under light and thermal stress. With configuration of PeLEDs with 60% EABr, as high as 12.1% EQE of sky-blue electroluminescence located at 488 nm has been demonstrated, which will pave the way for the full color display for the PeLEDs.
Reactive oxygen species (ROS) are byproducts of aerobic metabolism and potent agents that cause oxidative damage. In oxygenic photosynthetic organisms such as cyanobacteria, ROS are inevitably ...generated by photosynthetic electron transport, especially when the intensity of light-driven electron transport outpaces the rate of electron consumption during CO₂ fixation. Because cyanobacteria in their natural habitat are often exposed to changing external conditions, such as drastic fluctuations of light intensities, their ability to perceive ROS and to rapidly initiate antioxidant defences is crucial for their survival. This review summarizes recent findings and outlines important perspectives in this field.
To investigate toxic effects of microplastic on marine microalgae Skeletonema costatum, both algal growth inhibition test and non-contact shading test were carried out, and algal photosynthesis ...parameters were also determined. The SEM images were used to observe interactions between microplastic and algae. It was found that microplastic (mPVC, average diameter 1 μm) had obvious inhibition on growth of microalgae and the maximum growth inhibition ratio (IR) reached up to 39.7% after 96 h exposure. However, plastic debris (bPVC, average diameter 1 mm) had no effects on growth of microalgae. High concentration (50 mg/L) mPVC also had negative effects on algal photosynthesis since both chlorophyll content and photosynthetic efficiency (ΦPSⅡ) decreased under mPVC treatments. Shading effect was not one reason for toxicity of microplastic on algae in this study. Compared with non-contact shading effect, interactions between microplastic and microalage such as adsorption and aggregation were more reasonable explanations for toxic effects of microplastic on marine microalgae. The SEM images provided a more direct and reasonable method to observe the behaviors of microplastic.
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•The toxicity of microplastic depended on their particle size.•The microplastic had negative effects on growth and photosynthesis of microalgae.•Shading effect was not one of reasons for toxic effects of microplastic in this study.•Interactions between microplastic and microalgae observed with SEM technique were direct and reasonable explanations for toxic effects of microplastic.
Interactions between microplastic and microalage were directly and clearly observed with SEM technique to investigate negative effects of microplastic on microalage.
Checkpoint blockade therapy, for example using antibodies against CTLA-4 and PD-1/PD-L1, relieves T cells from the suppression by inhibitory checkpoints in the tumor microenvironment; thereby ...achieving good outcomes in the treatment of different cancer types. Like T cells, natural killer (NK) cell inhibitory receptors function as checkpoints for NK cell activation. Upon interaction with their cognate ligands on infected cells, tumor cells, dendritic cells and regulatory T cells, signals from these receptors severely affect NK cells' activation and effector functions, resulting in NK cell exhaustion. Checkpoint inhibition with antagonistic antibodies (Abs) can rescue NK cell exhaustion and arouse their robust anti-tumor capacity. Most notably, the response to anti-PD-1 therapy can be enhanced by the increased frequency and activation of NK cells, thereby increasing the overall survival of patients with multiple types of cancer. In addition, rescue of NK cell activity could enhance adaptive T cells' anti-tumor activity. Some antagonistic Abs (e.g., anti-TIGIT and anti-NKG2A monoclonal Abs) have extraordinary potential in cancer therapy, as evidenced by their induction of potent anti-tumor immunity through recovering both NK and T cell function. In this review, we summarize the dysfunction of NK cells in the tumor microenvironment and the key NK cell checkpoint receptors or molecules that control NK cell function. We particularly focus on recent advances in the most promising strategies through blockade of NK cell checkpoints or their combination with other approaches to more effectively reject tumors.
A 2D polypseudorotaxane-type assembly was constructed using cucurbit8uril and styrylpyridinium-bearing triphenylamine. In addition, tunable non-covalent to covalent transition was achieved by 2+2 ...photodimerization of styrylpyridinium units. Thus, a more stable 2D polyrotaxane-type nanoarchitecture was obtained, which could capture 60fullerene and further exhibit an excellent photodynamic therapy effect.
A stable 2D supramolecular assembly was constructed with photoreaction-driven transformation from polypseudorotaxane to polyrotaxane, which could capture C
60
in water and present excellent DNA cleavage ability and photodynamic therapy effect.
Lamellar and helical supramolecular assemblies were constructed using cucurbiturils and a naphthalenediimide derivative. More interestingly, the formation of the lamellar assembly could be reversibly ...photocontrolled via competitive binding with α-cyclodextrin and water-soluble azobenzene.
Secure Auditing and Deduplicating Data in Cloud Li, Jingwei; Li, Jin; Xie, Dongqing ...
IEEE transactions on computers,
2016-Aug.-1, 2016-8-1, 20160801, Letnik:
65, Številka:
8
Journal Article
Recenzirano
As the cloud computing technology develops during the last decade, outsourcing data to cloud service for storage becomes an attractive trend, which benefits in sparing efforts on heavy data ...maintenance and management. Nevertheless, since the outsourced cloud storage is not fully trustworthy, it raises security concerns on how to realize data deduplication in cloud while achieving integrity auditing. In this work, we study the problem of integrity auditing and secure deduplication on cloud data. Specifically, aiming at achieving both data integrity and deduplication in cloud, we propose two secure systems, namely SecCloud and SecCloud<inline-formula><tex-math notation="LaTeX">^+ </tex-math> <inline-graphic xlink:type="simple" xlink:href="li-ieq1-2389960.gif"/> </inline-formula>. SecCloud introduces an auditing entity with a maintenance of a MapReduce cloud, which helps clients generate data tags before uploading as well as audit the integrity of data having been stored in cloud. Compared with previous work, the computation by user in SecCloud is greatly reduced during the file uploading and auditing phases. SecCloud <inline-formula><tex-math notation="LaTeX">^+</tex-math> <inline-graphic xlink:type="simple" xlink:href="li-ieq2-2389960.gif"/> </inline-formula> is designed motivated by the fact that customers always want to encrypt their data before uploading, and enables integrity auditing and secure deduplication on encrypted data.
While hundreds of consistently altered metabolic genes had been identified in hepatocellular carcinoma (HCC), the prognostic role of them remains to be further elucidated. Messenger RNA expression ...profiles and clinicopathological data were downloaded from The Cancer Genome Atlas—Liver Hepatocellular Carcinoma and GSE14520 data set from the Gene Expression Omnibus database. Univariate Cox regression analysis and lasso Cox regression model established a novel four‐gene metabolic signature (including acetyl‐CoA acetyltransferase 1, glutamic‐oxaloacetic transaminase 2, phosphatidylserine synthase 2, and uridine‐cytidine kinase 2) for HCC prognosis prediction. Patients in the high‐risk group shown significantly poorer survival than patients in the low‐risk group. The signature was significantly correlated with other negative prognostic factors such as higher α‐fetoprotein. The signature was found to be an independent prognostic factor for HCC survival. Nomogram including the signature shown some clinical net benefit for overall survival prediction. Furthermore, gene set enrichment analyses revealed several significantly enriched pathways, which might help explain the underlying mechanisms. Our study identified a novel robust four‐gene metabolic signature for HCC prognosis prediction. The signature might reflect the dysregulated metabolic microenvironment and provided potential biomarkers for metabolic therapy and treatment response prediction in HCC.
We established and validated a novel four‐gene metabolic signature (including ACAT1, GOT2, PTDSS2, and UCK2) for HCC prognosis prediction. Patients in the high‐risk group shown significantly poorer survival than patients in the low‐risk group. The signature might reflect the dysregulated metabolic microenvironment and provided potential biomarkers for metabolic therapy and treatment response prediction in HCC.
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