The
direct utilization of abundant and cheap elemental sulfur (S)
to synthesize sulfur quantum dots (SQDs) with satisfactory yield and
photoluminescence quantum yield (PLQY) remains a big challenge. Here,
we report a simple and effective method for mass-producible synthesis
of ultrabright fluorescent SQDs based on one-pot solvothermal treatment
of S-ethylenediamine (S-EDA) solution. The PLQY of synthesized SQDs
and the corresponding S-to-SQDs conversion efficiency (CE) can reach
as high as 87.8% and 15.9%, respectively, both of which are the highest
values to date. In addition, the SQDs simultaneously show good water
solubility, superior storage stability, stable fluorescence against
ionic strength variation and pH change, and low toxicity, which enable
them promising for numerous applications such as fabrication of fluorescent
polymer composite and ink. Furthermore, SQDs also present strong two-photon
emission, and their use for two-photon fluorescence imaging is reported
here for the first time. This work thus highlights enormous opportunities
not only for bringing SQDs from laboratory research to real applications
but also for the value-added utilization of S resource.
Luteolin, a polyphenolic flavone, has been demonstrated to exert anti-tumor activity in various cancer types. Cisplatin drug resistance is a major obstacle in the management of ovarian cancer. In the present study, we investigated the chemo-sensitizing effect of luteolin in both cisplatin-resistant ovarian cancer cell line and a mice xenotransplant model. In vitro, CCK-8 assay showed that luteolin inhibited cell proliferation in a dose-dependent manner, and luteolin enhanced anti-proliferation effect of cisplatin on cisplatin-resistant ovarian cancer CAOV3/DDP cells. Flow cytometry revealed that luteolin enhanced cell apoptosis in combination with cisplatin. Western blotting and qRT-PCR assay revealed that luteolin increased cisplatin-induced downregulation of Bcl-2 expression. In addition, wound-healing assay and Matrigel invasion assay showed that luteolin and cisplatin synergistically inhibited migration and invasion of CAOV3/DDP cells. Moreover, in vivo, luteolin enhanced cisplatin-induced reduction of tumor growth as well as induction of apoptosis. We suggest that luteolin in combination with cisplatin could potentially be used as a new regimen for the treatment of ovarian cancer.
This study reports the presence of two fractions from corn seeds inhibitory to aflatoxin formation. Using a sensitive laboratory assay that can measure both inhibition of fungal growth and inhibition of aflatoxin biosynthesis, we examined aqueous extracts from seeds of Tex6, a corn inbred shown to be highly resistant to aflatoxin accumulation in field and laboratory evaluations. In these extracts, we identified two biologically active fractions. One inhibited growth of Aspergillus flavus and, thus, aflatoxin accumulation, and the other inhibited aflatoxin formation with little effect on fungal growth. The compounds responsible for these activities appear to be proteaceous, as they are water soluble, heat labile, and sensitive to proteinase K treatment. The compounds were partially purified by ultrafiltration and chromatography. The estimated molecular mass of the growth inhibitor is approximately 28 kDa, and that of the aflatoxin biosynthesis inhibitor appears to be greater than 100 kDa. Partially purified preparations of the growth inhibitor and aflatoxin biosynthesis inhibitor cause 50% inhibition at 26 and 75 mug of protein/ml, respectively. The presence of these compounds in Tex6 may explain its resistance to aflatoxin accumulation.
Alzheimer's disease (AD) is the most common neurodegenerative disorder and the main cause of dementia among the elderly worldwide. Unfortunately, the mechanism of AD remains unclear, and no effective therapies are available yet. An increasing amount of studies have demonstrated that long non-coding RNAs (LncRNAs) play a notable role in the pathogenesis of plenty of human diseases, and they have served as biomarkers and potential therapeutic targets. However, the function of LncRNAs in AD remains unclear. This study aimed to explore the potential role of LncRNA nuclear enriched abundant transcript 1 (NEAT1) in AD. We found that LncRNA NEAT1 was upregulated in the AD animal models. Furthermore, we demonstrated that NEAT1 could interact with NEDD4L and promote PTEN-induced putative kinase 1 (PINK1)'s ubiquitination and degradation and then impaired PINK1-dependent autophagy. Collectively, the lncRNA NEAT1 promotes the pathogenesis of AD and serves as a promising novel target for pharmacological intervention.
A seven-gene operon for the synthesis of phenazine-1-carboxylic acid was introduced into Pseudomonas fluorescens Q8r1-96, an aggressive root colonizer that produces 2,4-diacetylphloroglucinol and consistently suppresses take-all of wheat. The recombinant strains produced both antifungal metabolites and maintained population sizes comparable to those of Q8r1-96 over a seven-week period in the rhizosphere of wheat. The strains were no more suppressive of take-all or Pythium root rot than was Q8r1-96, but suppressed Rhizoctonia root rot at a dose of only 10(2) CFU per seed, one to two orders of magnitude lower than the dose of Q8r1-96 required for comparable disease control.
Autonomous vehicle technology is greatly valued nowadays, and an active collision avoidance system is one of the key parts for autonomous driving. This study presents a comprehensive architecture of an active collision avoidance system for an autonomous vehicle, which is integrated with a decision-making module, a path-planning module, a lateral-path-following module and a fuzzy adaptive following module (longitudinal motion) to deal with potential hazards on a straight road or a curved road. In order to make the planned path for overtaking manoeuvres safer, an improved harmonic velocity potential approach for path planning is presented, which innovatively enhances the effect of an obstacle potential on a road by adding a scale term, so that it can generate a smooth path for a vehicle-overtaking manoeuvre. All the potentials which are used for vehicle lane keeping or lane changing are well designed. The lateral-path-following module is based on the constrained linear model predictive control approach, which ensures that the host vehicle can follow the planned path precisely. Furthermore, when the overtaking manoeuvre is not suitable, the fuzzy adaptive following module is utilized to ensure that the host vehicle can adaptively keep a safe distance from the preceding vehicle. Tactical decisions, such as overtaking, accelerating or decelerating, are determined by the decision-making module. Finally, several typical scenarios with low traffic on a straight road or a curved road are simulated to verify the effectiveness and the feasibility of the active collision avoidance system. The simulation results show that the host vehicle can make a successful collision avoidance manoeuvre without the intervention of a human driver in different situations.
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