N6‐methyladenosine (m6A) is a well‐known modification of RNA. However, as a key m6A methyltransferase, METTL16 has not been thoroughly studied in gastric cancer (GC). Here, the biological role of ...METTL16 in GC and its underlying mechanism was studied. Immunohistochemistry was used to detect the expression of METTL16 and relationship between METTL16 level and prognosis of GC was analysed. CCK8, colony formation assay, EdU assay and xenograft mouse model were used to study the effect of METTL16. Regulatory mechanism of METTL16 in the progression of GC was studied through flow cytometry analysis, RNA degradation assay, methyltransferase inhibition assay, RT‐qPCR and Western blotting. METTL16 was highly expressed in GC cells and tissues and was associated with prognosis. In vitro and in vivo experiments confirmed that METTL16 promoted proliferation of GC cells and tumour growth. Furthermore, down‐regulation of METTL16 inhibited proliferation by G1/S blocking. Significantly, we identified cyclin D1 as a downstream effector of METTL16. Knock‐down METTL16 decreased the overall level of m6A and the stability of cyclin D1 mRNA in GC cells. Meanwhile, inhibition of methyltransferase activity reduced the level of cyclin D1. METTL16‐mediated m6A methylation promotes proliferation of GC cells through enhancing cyclin D1 expression.
The widely used pseudorabies virus (PRV) Bartha-K61 vaccine has played a key role in the eradication of PRV. Since late 2011, however, a disease characterized by neurologic symptoms and a high number ...of deaths among newborn piglets has occurred among Bartha-K61-vaccinated pigs on many farms in China. Clinical samples from pigs on 15 farms in 6 provinces were examined. The PRV gE gene was detectable by PCR in all samples, and sequence analysis of the gE gene showed that all isolates belonged to a relatively independent cluster and contained 2 amino acid insertions. A PRV (named HeN1) was isolated and caused transitional fever in pigs. In protection assays, Bartha-K61 vaccine provided 100% protection against lethal challenge with SC (a classical PRV) but only 50% protection against 4 challenges with strain HeN1. The findings suggest that Bartha-K61 vaccine does not provide effective protection against PRV HeN1 infection.
Abstract
Binary stars ubiquitous throughout the Universe are important. Contact binaries (CBs) possessing period–luminosity (PL) relations could be adopted as distance tracers. The PL relations of ...CBs are influenced by metallicity abundance and color index, which are connected to both the radius and luminosity of stars. Here we propose fine relations of the period–luminosity–metallicity–color (PLZC) from the ultraviolet to infrared bands based on current surveys. The accuracy of the distance estimation is 6% and 8%, respectively, depending on the PLZC relations of the CBs in the infrared and optical bands of the collected data. PLZC models are still more accurate than PLC models in determining intrinsic luminosity, notwithstanding their limited improvement. Meanwhile, these relations based on synthetic photometry are also calibrated. On the basis of the synthetic photometry, a 6% accuracy of distance is estimated. The measured or synthetic data of PLZC or PLC relations in infrared bands comes first in the list of suggestions for distance estimations and is followed by the measured data of optical bands.
Ag2S quantum dots (QDs) with high photoluminescence quantum yield (PLQY) in the second near‐infrared (NIR‐II, 1000–1700 nm) window are urgently pursued. Halide atoms (especially chloride) have been ...studied as inorganic capping ligands on improving the PLQY of Cd‐, Pb‐based chalcogenide QDs; however, it remains a challenge to well replace the organic ligand with chloride ligand from silver chalcogenide QDs. Herein, a novel strategy to prepare Ag2S QDs with significant photoluminescence (PL) enhancement via chloride‐mediated growth and passivation is demonstrated. The oleylamine and oleate ligands on the surface of silver‐rich Ag2S QDs are readily replaced by chloride ligands due to the smaller size and higher binding affinity with Ag+. Upon partial ligand exchange and chloride passivation, the surface trap states in Ag2S QDs are reduced through a decrease of unsaturated surface Ag atoms. Therefore, Ag2S QDs with approximately 300‐fold enhancement of PL intensity, and a PLQY of 47.6% at 1220 nm emission, and a lifetime of 256 ns are obtained because the nonradiative recombination is inhibited. This work reveals that the passivation of Ag2S QDs with chloride ligands is fully feasible, providing new insights into improving the PLQY of silver chalcogenide QDs.
300‐fold photoluminescence (PL) enhancement of Ag2S quantum dots (QDs) is achieved via chloride‐mediated growth and passivation, and the PL quantum yield (PLQY) reaches 47.6%. Due to the partial ligand exchange and chloride passivation, Ag dangling bond on the surface of Ag2S QDs is saturated, so that the surface trap states are reduced and the nonradiative recombination is suppressed.
Smart voltage-gated nanofiltration membranes have enormous potential for on-demand and precise separation of similar molecules, which is an essential element of sustainable water purification and ...resource recovery. However, the existing voltage-gated membranes are hampered by limited selectivity, stability, and scalability due to electroactive monomer dimerization. Here, for the first time, the host–guest recognition properties of cucurbit7uril (CB7) are used to protect the viologen derivatives and promote their assembly into the membrane by interfacial polymerization. Viologen functions as a voltage switch, whereas CB7 complexation prevents its dimerization and improves its redox stability. The inhibited diffusion of the CB7-viologen complex enables the precise patterning of the surface structure. The resultant voltage-gated membrane displays 80% improved rejection performance, excellent recovery accuracy for similar molecules, and anti-fouling properties. This work not only provides an innovative strategy for the preparation of voltage-gated smart nanofiltration membranes but also opens up new avenues for ion-selective transmission in water treatment, bionic ion channels, and energy conversion.
This study aims to develop a new strategy to fabricate nanofiltration (NF) membranes with high removal efficiency for heavy metal ions in wide acidic pH range. Unlike conventional polyacrylonitrile ...(PAN) based thin film composite (TFC) membranes that requires multiple coating steps, the new NF membrane was fabricated through direct interfacial polymerization with positively charged polyethyleneimine (PEI) on PAN substrates blended with sulfonated polyarylene ether benzonitrile (SPEB). The unique surface migration effect of SPEB led to a smoother, more hydrophilic surface and sponge-like structure of the substrate. Such a modified structure was found to be crucial to achieve smaller pore size as well as better adhesion of the selective layer and the substrate of the modified TFC membrane. The resultant NF membrane has a reasonably high pure water permeability of 7.62 ± 0.81 LMH·bar−1, and a molecular weight cut-off of 300 Da. It achieved a reasonably high rejection towards heavy metal cations such as Pb2+, Cd2+, Ni2+ over 93.0% in a wide acidic pH range. This work may provide insightful guidelines for upgrading current NF membranes for heavy metal removals in harsh acidic environments.
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•Blending SPEB with PAN improves the binding force between selective and substrate.•Surface migration effect of SPEB enhances the hydrophilicity and porosity.•The membrane possesses high rejection towards various heavy metals in acidic pH range.
Abstract
Recent observations have revealed a population of
α
-element abundances, enhanced giant stars with unexpected high masses (≳1
M
⊙
) from asteroseismic analysis and spectroscopy. Assuming ...single-star evolution, their masses imply young ages (
τ
< 6 Gyr) incompatible with the canonical Galactic chemical evolution scenario. Here we study the chemistry and kinematics of a large sample of such
α
-rich, high-mass red giant branch (RGB) stars drawn from the LAMOST spectroscopic surveys. Using LAMOST and Gaia, we found these stars share the same kinematics as the canonical high-
α
old stellar population in the Galactic thick disk. The stellar abundances show that these high-
α
massive stars have
α
- and iron-peak element abundances similar to those of the high-
α
old thick-disk stars. However, a portion of them exhibit higher (N+C)/Fe and Ba/Fe ratios, which implies they have gained C- and Ba-rich materials from extra sources, presumably asymptotic giant branch (AGB) companions. The results support the previous suggestion that these RGB stars are products of binary evolution. Their high masses thus mimic “young” single stars, yet in fact they belong to an intrinsic old stellar population. To fully explain the stellar abundance patterns of our sample stars, a variety of binary evolution channels, such as main-sequence (MS) + RGB, MS + AGB, RGB + RGB, and RGB + AGB, are required, pointing to diverse formation mechanisms of these seemly rejuvenated cannibals. With this larger sample, our results confirm earlier findings that most, if not all,
α
-rich stars in the Galactic disk seem to be old.
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