Journals
2018 EN
Jing Chen · Baofeng Liu · Zhongzhou Yang
+5 more
In this study, we systematically investigated the fate and phytotoxicity of carbon nanodots (C-dots, about 3 nm) in Arabidopsis thaliana (Arabidopsis), as well as the underlying potential mechanisms, by integrating transcriptomic, physiological and metabolomic techniques. The phytotoxicity of C-dots in Arabidopsis was concentration-dependent. C-dots at 125, 250, 500 and 1000 mg L−1 significantly reduced the root elongation by 25%, 40%, 56% and 61%, respectively, compared with the control groups, while no significant inhibition was observed in 62.5 mg L−1 C-dot exposure. RNA-seq analyses showed that 715 and 636 genes in Arabidopsis roots and shoots, respectively, were up-regulated by 1000 mg L−1 C-dots, which were involved in stimulus response, UDP-glycosyltransferase activity and cellular response to phosphate starvation. Meanwhile, 552 and 707 down-regulated genes in roots and shoots, respectively, were mainly involved in chloroplast structure and function. Furthermore, obvious physiological responses were found in plants exposed to 1000 mg L−1 C-dots, e.g., the activities of glutathione reductase significantly increased by 1.8 and 2.4 times in Arabidopsis roots and shoots in contrast to controls, respectively, while the activity of three photosynthesis enzymes (Rubisco, FBP and FDA) in Arabidopsis shoots was reduced by 38%, 22% and 34%, respectively. Based on gas chromatography-mass spectrometry, untargeted metabolomic analyses revealed that the contents of 13 and 22 metabolites were significantly changed in the root and shoots exposed to 1000 mg L−1 C-dots, respectively. In conclusion, the results of this study could provide insights into the molecular mechanisms of the phytotoxic effects of C-dots on plants.
Royal Society of Chemistry
Journals
2018 EN
Lieshu Tong · Josef Kauer-Bonin · Xi Chen
+3 more
Elastic light scattering and machine learning accurately discriminates between healthy children, those with iron deficiency, and those with thalassemia minor.
Royal Society of Chemistry
Journals
2018 EN
Haiyang Chen · Peiran Song · Yanyan Diao
+10 more
Bruton's tyrosine kinase (BTK) plays a critical role in B cell receptor (BCR)-mediated signaling pathways responsible for the development and function of B cells, which makes it an attractive target for the treatment of many types of B-cell malignancies. Herein, a series of N5-substituted 6,7-dioxo-6,7-dihydropteridine-based, irreversible BTK inhibitors were reported with IC 50 values ranging from 1.9 to 236.6 nM in the enzymatic inhibition assay. Compounds 6 and 7 significantly inhibited the proliferation of Ramos cells which overexpress the BTK enzyme, as well as the autophosphorylation of BTK at Tyr223 and the activation of its downstream signaling molecule PLCγ2. Overall, this series of compounds could provide a promising starting point for further development of potent BTK inhibitors for B-cell malignancy treatment.
Royal Society of Chemistry
Journals
2018 EN
Ye Guo · Pan-Pan Zhou · Senyan Zhang
+3 more
AIDS has evolved from a fatal infectious disease to a manageable chronic disease under the treatment of anti-AIDS medications. HIV fusion inhibitors with high activity, low side effects and strong selectivity are promising drugs against HIV. Only one fusion inhibitor is currently approved, thereby highly active long-acting fusion inhibitors need to be developed for long-term AIDS treatment. Here, we synthesised MT-SC22EK (a small HIV fusion inhibitor) derivatives containing 1-2 staples to improve its stability. Antiviral activity studies showed that MT-SC22EK-2 with two staples exhibited potent inhibitory activity against HIV-1 standard strains and Chinese epidemic strains, and at the same time, MT-SC22EK-2 presented strong anti-T20 resistance. Surprisingly, MT-SC22EK-2 possessed excellent protease stability with a half-life of 3665 min. MT-SC22EK-2 is a potential HIV fusion inhibitor considered as a long-acting anti-HIV drug candidate.
Royal Society of Chemistry
Journals
2018 EN
Linlin Zang · Ru Lin · Tianwei Dou
+3 more
Nanofibrous membranes have a high specific surface area and large porosity, which are beneficial for being used as adsorbents to remove heavy metal ions from water. In this work, electrospun nanofibers were wrapped with a hydrogel layer with a tunable thickness, which endowed the membrane with excellent superhydrophilic performance. Because of good water-retention properties and abundant functional groups originating from the hydrogel layer, as a static adsorbent, the maximum adsorption capacity of Pb(II) was up to 146.21 mg g−1 according to the Langmuir model. Meanwhile, the electrospun membrane also possessed water permeability as a flow-through membrane for dynamic adsorption, which was obviously different from traditional hydrogel adsorbents. As a result, the rejection ratio of Pb(II) can remain over 55% after running for 72 h under high pH conditions and at low initial ion concentrations. Apart from these, cycle operations confirmed the regeneration of the membrane, and competitive adsorption experiments illustrated the selective removal of Pb(II) in a mixed ion solution.
Royal Society of Chemistry
Journals
2018 EN
Guoqiang Zhao · Yue Lin · Kun Rui
+4 more
Constructing heterostructures is an effective strategy for designing efficient electrocatalysts. MoS2 is a star catalyst for hydrogen evolution reaction (HER) in acidic media; however, the alkaline HER activity is deficient due to the sluggish water dissociation process. Herein, Ni(OH)2/MoS2 heterostructures with Ni(OH)2 nanoclusters epitaxially decorated on the surface of MoS2 are synthesized towards the alkaline HER. As compared with MoS2, the epitaxial Ni(OH)2/MoS2 heterostructures show significantly enhanced HER activity in 1 M KOH, and the overpotential is decreased by nearly 150 mV to reach a current density of 10 mA cm-2. The substantial increase in turnover frequency (TOF) demonstrates that the intrinsic activity is greatly improved after the incorporation of Ni(OH)2 nanoclusters. The presence of Ni(OH)2 nanoclusters would provide additional water dissociation sites while MoS2 is ready for the adsorption and combination of the generated H*, and this so-called synergistic effect eventually induces significantly enhanced alkaline HER kinetics. Besides, the electron transfer from Ni(OH)2 to MoS2 increases the proton affinity of MoS2. The present results describe an interesting case of an atomic-scale electrochemically inert material promoted HER process, and would open a new avenue into designing efficient hetero-nanostructures towards electrocatalytic applications.
Royal Society of Chemistry
Journals
2018 EN
Qian Zhou · Guoqiang Zhao · Kun Rui
+4 more
The sluggish reaction kinetics of the hydrogen evolution reaction (HER) in alkaline media is a great obstacle to alkaline water electrolysis, and it remains a great challenge to develop precious metal-free efficient catalysts for the alkaline HER. Transition metal dichalcogenides (TMDs), in particular MoS2 and MoSe2, are promising catalysts for the HER in acidic media, but they exhibit much inferior catalytic activity for the alkaline HER owing to the slow water dissociation process. In this work, we, for the first time, demonstrate that TMD heterostructures with abundant edge sites deliver substantially accelerated alkaline HER kinetics, which is in great part due to the enhanced water adsorption/dissociation capability. As a proof of concept, MoS2/MoSe2 heterostructures with ultrasmall MoS2 nanoclusters anchored on MoSe2 nanosheets are synthesized via a solution-phase process and are investigated as alkaline HER catalysts in detail. MoSe2 nanosheets serve as excellent substrates to hinder the agglomeration of MoS2 nanoclusters, resulting in abundant edge sites. Benefiting from the decent water adsorption/dissociation capability of the edge sites, the optimal MoS2/MoSe2 heterostructure shows exceptional catalytic activity in 1 M KOH with an overpotential of 235 mV at 10 mA cm-2 and a Tafel slope of 96 mV dec-1, which is substantially improved as compared with the individual MoSe2 (330 mV, 135 mV dec-1) and MoS2 (400 mV, 157 mV dec-1). The success of this catalyst design strategy for enhancing alkaline HER kinetics is also demonstrated in MoSe2/MoSe2 and MoS2/MoS2 heterostructures. The results suggest that engineering additional edge sites that have a strong affinity for H2O is critical for TMDs towards enhanced alkaline HER activity, and also open new avenues in the design of precious metal-free efficient catalysts for the alkaline HER.
Royal Society of Chemistry
Journals
2018 EN
Qunfang Zhou · Songsong Wu · Ningqiang Gong
+6 more
Correction for 'Liposomes loading sodium chloride as effective thermo-seeds for microwave ablation of hepatocellular carcinoma' by Jie Yu, Ping Liang et al., Nanoscale, 2017, 9, 11068-11076.
Royal Society of Chemistry
Journals
2018 EN
Jinyan Xiong · Xulei Du · Gang Cheng
+4 more
Constructing one-dimensional (1D) hierarchical photocatalysts is deemed to be central to promoting photocatalytic capacity. In this paper, 1D hierarchical structures composed of CdS nanosheets/nanoparticles on Ag nanowires (denoted as 1D Ag@CdS core–shell hierarchical hetero-nanowires) have been fabricated via a wet-chemistry approach at low temperature. The optimization of the synthetic parameters indicates that the amounts of Cd(NO3)2·4H2O and thiourea play important roles in the construction of the 1D hierarchical structures. The as-prepared 1D hierarchical Ag@CdS core–shell hetero-nanowires exhibit efficient photocatalytic performance in both methyl orange (MO) degradation (degrade 96% of MO within 240 min) and hydrogen generation (73.5 μmol h−1) from water splitting due to the unique hybrid nano-architecture. It is expected that this Ag@CdS hierarchical nanostructure could have potential in solar energy conversion and this fabrication technique could be used as a reference to design other 1D metal@semiconductor core–shell heteronanowires.
Royal Society of Chemistry
Journals
2018 EN
Qing Zhou · Ziyi Wang · Xueyu Dou
+4 more
Deciphering the emission mechanism of nonconventional luminogens and achieving persistent room temperature phosphorescence (p-RTP) from pure organic compounds have drawn increasing attention due to their significant fundamental importance and promising applications. Previous reports on nonconventional luminogens, however, mainly focus on fluorescence, while advances in pure organic p-RTP are generally restricted to aromatic crystals or host–guest systems. Herein, we report the unique intrinsic emission and moreover p-RTP in amorphous nonaromatic polymers of poly(acrylic acid) (PAA), polyacrylamide (PAM) and poly(N-isopropylacrylamide) (PNIPAM). These polymers are nonluminescent in dilute solutions, while being highly emissive in concentrated solutions, nanosuspensions and solid powders/films. This can be rationalized by the clustering-triggered emission (CTE) mechanism, as supported by further thermoresponsive emission, cryogenic and aggregation-induced emission (AIE) experiments, alongside single crystal analysis. Furthermore, PAA and PAM solids under ambient conditions, and PNIPAM solids under vacuum or under nitrogen, demonstrate distinct p-RTP, which can be enhanced through further ionization or pressurization. These results not only refresh our understanding of the emission mechanism of nonaromatic polymers, but also enable the facile fabrication and application of pure organic p-RTP luminogens from readily available compounds, thus providing an important step forward in both nonconventional luminogens and p-RTP.
Royal Society of Chemistry