As a burgeoning research field, ultrasound-responsive materials have attracted intense interest in healthcare research. However, the basic mechanism of sonochemical effect in the quasi-solid state is far from being well understood than those in the solution. Herein, we showcase mechanochemical transformations of europium(Ⅲ) complexes in a supramolecular hydrogel matrix. With the combination of labile terpyridine-europium complexes(TPY-Eu^(3+)) as mechanochromic moieties and an ultrasound-responsive fluorogen(URF) as a molecular tweezer, the hydrogel produces a notable fluorescence change in response to ultrasound. The mechanochemical transformation was elucidated by molecular dynamics(MD) simulations, and fully probed and evidenced by electrochemical experiments, X-ray photoelectron spectroscopy(XPS), and attenuated total reflectance-Fourier transform infrared(ATR-FTIR) spectroscopy.
Benzothiazoles(BTHs)and benzotriazoles(BTRs)are an important group of industrial chemicals.Due to large scale and long-term applications,they have been released to various environmental media,including indoor dust,and subsequently elicited a variety of toxic effects.In this study,the concentrations and composition profiles of BTHs and BTRs in indoor dust from Suizhou and Beijing,China,were investigated.The median concentrations ofΣ_(6)BTHs in indoor dust samples from Suizhou and Beijing were 133 and 439 ng/g dw,respectively,whereas theΣ5BTRs concentrations from Suizhou and Beijing were 28.4 and 40.1 ng/g dw,respectively(dw=dry weight).BTH,2-OH-BTH,1-H-BTR,and 5-Me-1-H-BTR were the predominant compounds in the dust.Human exposure to such chemicals was further evaluated.The intake for the population in Suizhou(0.163–0.939 ng/kg bw/day)and Beijing(0.0347–0.200 ng/kg bw/day)was minor(bw=body weight).The obtained results in this study will be able to add insight into human exposure to BTHs and BTRs.This study will help to identify the behavior and fate of BTHs and BTRs in the environment,and thus to scientifically assess their risk of exposure.
Herein a series of combretastatin A-4(CA-4)analogues with aggregation-induced emission characteristics(compounds a1-a19)were rationally designed and synthesized.The research results showed that the mechanism of AIE of a1-a19 could be attributed to the dual function of the restriction of intramolecular motion(RIM)and J-aggregate formation.Furthermore,the detailed investigation on the action mechanisms revealed that a19 diffused from lysosomes into the cytoplasm,and then targeted the colchicine binding site to induce cell cycle arrest and apoptosis in cancer cells.These results provide new ideas and impetus for the rational design of CA-4 analogues.
The monocrystalline LiNbO_(3)(LN)and LiTaO_(3)(LT)plates have been qualified as a kind of material platform for high performance RF filter that is considerable for the 5G communication.LN and LT thin films are usually transferred on handle wafers by combining ion-slicing and wafer bonding technique to form a piezoelectric on insulator(POI)substrate.The ion implantation is a key process and the implantation-induced strain is essential for the layer transfer.Here,we reported the strain profile of ion implanted rotated Y-cut LN and LT.The ion implantation generates the out-of-plane tensile strain of the sample surface and(006)plane,while both the tensile and compressive strain are observed on the(030)plane.The implanted ions redistributed due to the anisotropy of LN and LT,and induce the main tensile normal to the(006)plane.Meanwhile,the(030)planes are contracted due to the Poisson effect with the interstitial ions disturbing and mainly show a compressive strain profile.
Zhongxu LiKai HuangYanda JiYang ChenXiaomeng ZhaoMin ZhouTiangui YouShibin ZhangXin Ou
Grain number is a flexible trait and contributes significantly to grain yield.In rice,the zinc finger transcription factor DROUGHT AND SALT TOLERANCE(DST)controls grain number by directly regulating cytokinin oxidase!dehydrogenase 2(OsCKX2)expression.Although specific upstream regulators of the DST-OsCKX2 module have been identified,the mechanism employed by DST to regulate the expression of OsCKX2 remains unclear.Here,we demonstrate that DST-interacting protein 1(DIP1),known as Mediator subunit OsMED25,acts as an interacting coactivator of DST.Phenotypic analyses revealed that OsMED25-RNAi and the osmed25 mutant plants exhibited enlarged panicles,with enhanced branching and spikelet number,similar to the dst mutant.Genetic analysis indicated that OsMED25 acts in the same pathway as the DST-OsCKX2 module to regulate spikelet number per panicle.Further biochemical analysis showed that OsMED25 physically interacts with DST at the promoter region of OsCKX2,and then recruits RNA polymerase II(Pol II)to activate OsCKX2 transcription.Thus,OsMED25 was involved in the communication between DST and Pol II general transcriptional machinery to regulate spikelet number.In general,our findings reveal a novel function of OsMED25 in DST-OsCKX2 modulated transcriptional regulation,thus enhancing our un derstanding of the regulatory mechanism underlying DST-OsCKX2-mediated spikelet number.
Lihao LinMinmin DuShuyu LiChuanlong SunFangming WuLei DengQian ChenChuanyou Li
We used transition radiation techniques instead of the original phosphor targets to improve the electronic beam diagnostic system at Beijing Free Electron Laser.The beam profile,size(3.3×2.4mm),position and divergence angle(σrms=2.5mrad)in transverse have been obtained from optical transition radiation.We also present the experimental set-up and some preliminary results.
Background:Promoting natural regeneration(including seed and sprout regeneration)of dominant woody species is essential for restoring secondary forests.However,such restoration processes have been decelerated by the enclosure under Natural Forest Protection Project of China(NFPP).It remains unclear how to implement appropriate management measures(e.g.,whether to apply logging and the suitable intensity)to facilitate natural regeneration according to the responses of two regeneration modes to management measures.We monitored the early stages of seed regeneration(seed rain,soil seed bank,and 1–3-year-old seedlings)and sprout regeneration(stump sprout rate,stump survival rate,probability of sprouting,and number of sprouts per stump)over the first 3 years(2017–2019)after logging under three intensity regimes(control[0%],25%,and 50%logging intensity)in secondary forests.Results:The seed rain density decreased markedly,seedling density increased insignificantly after logging,and logging promoted seedling survival at an increasing conversion rate of 3-year-old seedlings(37.5%under 0%,100%under 25%,and 80.95%under 50%logging)compared to those of the control.The proportion of 3-year-old seedlings increased with logging intensity and was the highest(16.2%)at 50%logging intensity.Sprout density was not affected by logging intensity,however,under 25%and 50%logging,it decreased by 27%and 6%in 2018,and by 37%and 33%in 2019,respectively.Seedling density was 41.65-and 15.31-fold higher than that of sprouts in the 50%and 25%logging treatments,respectively.Based on the relative contributions of the two regeneration modes after logging,three groups of natural regeneration patterns were classified for dominant woody species in temperate secondary forests,i.e.,seed regeneration preference(Betula dahurica,Carpinus cordata and Fraxinus mandshurica),sprout regeneration preference(Acer mono and Acer pseudosieboldianum)and no preference(Quercus mongolica,Fraxinus rhynchophylla,and Juglans mandshurica).Conclusion:In addition to enclosu
Rong LiQiaoling YanJin XieJing WangTing ZhangJiaojun Zhu
Organic carbonates(OCs)are a class of compounds featured by a carbonyl flanked by two alkoxy/aryloxy groups.They exist in either linear or cyclic forms,of which the majority encountered in nature adopt a pentacyclic structure.However,the enzymatic basis for pentacyclic carbonate ring formation remains elusive.Here,we reported that a four-protein metabolon(AlmUII-UV)assembled by a small peptide protein(AlmUV)appends a reactive N-hydroxylcarbamoyl moiety to the decarboxylated aldgamycins followed by a non-enzymatic condensation to give the pentacyclic carbonate ring.Our results have documented an unprecedent mechanism for carbonate formation.
Perovskite materials are promising candidates for the next generation of wearable optoelectronics.However,due to uncontrolled crystallization and the natural brittle property of crystals,it remains a great challenge to fabricate large-scale compact and tough perovskite film.Here we report a facile method to print large-scale perovskite films with high quality for flexible photodetectors.By introducing a soluble polyethylene oxide(PEO)layer during the inkjet printing process,the nucleation and crystal growth of perovskite is well controlled.Perovskite films can be easily printed in large scale and patterned in high resolution.Moreover,this method can be extended to various kinds of perovskite materials,such as MAPbb(MA=methylammonium),MA_(3)Sb_(2)l_(9),and(BA)_(2)PbBr_(4)(BA=benzylammonium).The printed perovskite films show high quality and excellent mechanical performance.The photodetectors based on the MAPbBr3 perovskite films show a responsivity up to -1,036 mAA/V and maintain over 96.8%of the initial photocurrent after 15,000 consecutive bending cycles.This strategy provides a facile approach to prepare large-scale flexible perovskite films.It opens up new opportunities for the fabrication of diverse wearable optoelectronic devices.
