Pangenome of water caltrop reveals structural variations and asymmetric subgenome divergence after allopolyploidization

Water caltrop(Trapa spp.,Lythraceae)is a traditional but currently underutilized non-cereal crop.Here,we generated chromosome-level genome assemblies for the two diploid progenitors of allotetraploid Trapa.natans(4x,AABB),i.e.,diploid T.natans(2x,AA)and Trapa incisa(2x,BB).In conjunction with four published(sub)genomes of Trapa,we used gene-based and graph-based pangenomic approaches and a pangenomic transposable element(TE)library to develop Trapa genomic resources.The pangenome displayed substantial gene-content variationwith dispensable and private gene clusters occupying a large proportion(51.95%)of the total cluster sets in the six(sub)genomes.Genotyping of presence-absence variation(PAVs)identified 40453 PAVs associated with 2570 genes specific to A-or B-lineages,of which 1428were differentially expressed,andwere enriched in organ development process,organic substancemetabolic process and response to stimulus.Comparative genome analyses showed that the allotetraploid T.natans underwent asymmetric subgenome divergence,with the B-subgenome being more dominant than the A-subgenome.Multiple factors,including PAVs,asymmetrical amplification of TEs,homeologous exchanges(HEs),and homeolog expression divergence,together affected genome evolution after polyploidization.Overall,this study sheds lights on the genome architecture and evolution of Trapa,and facilitates its functional genomic studies and breeding program.

Diverse O-methyltransferases catalyze the biosynthesis of floral benzenoids that repel aphids from the flowers of waterlily Nymphaea prolifera

Nymphaea is a key genus of the ANA grade(Amborellales,Nymphaeales,and Austrobaileyales)of basal flowering plants,which serve as a key model to study the early evolution of floral traits.In this study,we comprehensively investigated the emission,biosynthesis,and biological function of the floral scent in a night-blossoming waterlily Nymphaea prolifera.The headspace volatile collection combined with GC-MS analysis showed that the floral scent of N.prolifera is predominately comprised by methylated benzenoids including anisole,veratrole,guaiacol,and methoxyanisole.Moreover,the emission of these floral benzenoids in N.prolifera exhibited temporal and spatial pattern with circadian rhythm and tissue specificity.By creating and mining transcriptomes of N.prolifera flowers,12 oxygen methyltransferases(NpOMTs)were functionally identified.By in vitro enzymatic assay,NpOMT3,6,and 7 could produce anisole and NpOMT5,7,9,produce guaiacol,whereas NpOMT3,6,9,11 catalyzed the formation of veratrole.Methoxyanisole was identified as the universal product of all NpOMTs.Expression patterns of NpOMTs provided implication for their roles in the production of the respective benzenoids.Phylogenetic analysis of OMTs suggested a Nymphaea-specific expansion of the OMT family,indicating the evolution of lineage-specific functions.In bioassays,anisole,veratrole,and guaiacol in the floral benzenoids were revealed to play the critical role in repelling waterlily aphids.Overall,this study indicates that the basal flowering plant N.prolifera has evolved a diversity and complexity of OMT genes for the biosynthesis of methylated benzenoids that can repel insects from feeding the flowers.These findings provide new insights into the evolutional mechanism and ecological significance of the floral scent from early-diverged flowering plants.

Characteristics of oral methicillin-resistant Staphylococcus epidermidis isolated from dental plaque

The oral microbial community is widely regarded as a latent reservoir of antibiotic resistance genes. This study assessed the molecular epidemiology, susceptibility profile, and resistance mechanisms of 35 methicillin-resistant Staphylococcus epidermidis(MRSE) strains isolated from the dental plaque of a healthy human population. Broth microdilution minimum inhibitory concentrations(MICs) revealed that all the isolates were nonsusceptible to oxacillin and penicillin G. Most of them were also resistant to trimethoprim(65.7%) and erythromycin(54.3%). The resistance to multiple antibiotics was found to be largely due to the acquisition of plasmid-borne genes. The mec A and dfr A genes were found in all the isolates, mostly dfr G(80%), aac A-aph D(20%), aad D(28.6%), aph A3(22.9%), msr A(5.7%), and the erm C gene(14.3%). Classical mutational mechanisms found in these isolates were mainly efflux pumps such as qac A(31.4%), qac C(25.7%), tet K(17.1%), and nor A(8.6%). Multilocus sequence type analysis revealed that sequence type 59(ST59) strains comprised 71.43% of the typed isolates, and the e BURST algorithm clustered STs into the clonal complex 2-II(CC2-II). The staphyloccoccal cassette chromosome mec(SCCmec) type results showed that 25(71.43%) were assigned to type IV. Moreover, 88.66% of the isolates were found to harbor six or more biofilm-associated genes. The aap, atl E, embp, sdr F, and IS256 genes were detected in all 35 isolates. This research demonstrates that biofilm-positive multipleantibiotic-resistant ST59-SCCmec IV S. epidermidis strains exist in the dental plaque of healthy people and may be a potential risk for the transmission of antibiotic resistance.

Diketopyrrolopyrrole based D-π-A-π-D type small organic molecules as hole transporting materials for perovskite solar cells

Three novel diketopyrrolopyrrole （DPP） based small organic molecules were synthesized as hole transporting materials for perovskite solar cells. The effects of different donors and zr bridges on the performance of perovskite solar cells （PSCs） were discussed. The efficiency of TPADPP-1, TPADPP-2. PTZDPP-2 was 5.10%, 9.85% and 8.16% respectively. Compared to TPADPP-2, the voltage of PTZDPP-2 was higher. Because the electron-donatingability of phenothiazine based donor was larger than that of triphenylamine based donor, the HOMO level of PTZDPP-2 was lower than that of TPADPP-2. The results indicated that the diketopyrrolopyrrole based D-π-A-π-D type small organic molecule might be a promising hole trans- porting material in the perovskite solar cells.

Study on the Aromatic Components of Green Plum Wine by HS-SPME-GC-MS

In order to better blend green plum wine and study aromatic components of green plum wine,a qualitative analysis on aromatic components of soaked base liquor,green plum soaked wine,green plum juice,and fermented wine of green plum juice by Head Space Solid-phase Microextraction( HS-SPME) and Gas Chromatograph Mass Spectrometer( GC-MS) was studied in this paper. Experiment results indicated that14,32,17,and 46 kinds of aromatic components were identified respectively from four samples. Different aromatic components determined the special flavor and taste of green plum wine. Unique aromatic components generated in soaking process include benzaldehyde,1-butanol,2-methyl-,S-(-),benzoic acid ethyl ester,and 5-( hydroxymethyl). Special aromatic components in green plum juice were furfural,phenylethyl alcohol,and benzyl alcohol. The aromatic components in fermented wine of green plum juice mainly included phenylethyl alcohol( 6. 941%,relative content of peak area,same below),1-butanol,3-methyl-( 6. 940%),octanoic acid,ethyl ester( 3. 734%),decanoic acid,ethyl ester( 2. 590%),hexanoic acid,ethyl ester( 2. 479%),ethyl 9-decenoate( 2. 080%),and 5-hydroxymethyl( 1. 756%). This study was expected to provide scientific basis and data reference for quality improvement of green plum wine.

Fabrication of graphene nanoplatelets reinforced Mg matrix composites via powder thixoforging

A powder thixoforging route combined with slurry based mixing process was proposed to fabricate graphene nanoplatelets(GNPs) reinforced magnesium matrix composites(MgMCs). The originally spherical and ball-milled ZK60 powders were used as matrices, respectively.The mixing of 0.05 wt.% GNPs with the spherical powder led to GNPs clusters and degraded the mechanical properties of the composite.In contrast, with the addition of an optimal content(0.1 wt.%) of GNPs, the composite fabricated from ball-milled powder achieved a joint enhancement in tensile yield strength(52%) and fracture toughness(19%), demonstrating a pronounced strengthening efficiency of 650% and a good balance between strength and toughness. The ball-milled powder endowed the composite with a homogenous distribution of GNPs and a denser microstructure with reduced Mg-Zn eutectics, and the thixoforging process offered a well-bonded Mg/GNP interface, making full use of the strengthening and toughening potential of GNPs. Theoretical predication based on a modified shear-lag model suggested that load transfer dominated the strengthening mechanisms. In-situ tensile tests verified that crack deflection, secondary cracks and GNPs bridging mainly accounted for the toughening mechanisms. A numerical model with consideration of GNPs orientations was also established to understand the toughening effect from GNPs bridging.

A Face Recognition Algorithm Based on LBP-EHMM

In order to solve the problem that real-time face recognition is susceptible to illumination changes,this paper proposes a face recognition method that combines Local Binary Patterns(LBP)and Embedded Hidden Markov Model(EHMM).Face recognition method.The method firstly performs LBP preprocessing on the input face image,then extracts the feature vector,and finally sends the extracted feature observation vector to the EHMM for training or recognition.Experiments on multiple face databases show that the proposed algorithm is robust to illumination and improves recognition rate.

Environmentally persistent free radicals in PM_(2.5)from a typical Chinese industrial city during COVID-19 lockdown:The unexpected contamination level variation

The outbreak of COVID-19 has caused concerns globally.To reduce the rapid transmission of the virus,strict city lockdown measures were conducted in different regions.China is the country that takes the earliest home-based quarantine for people.Although normal industrial and social activities were suspended,the spread of virus was efficiently controlled.Simultaneously,another merit of the city lockdown measure was noticed,which is the improvement of the air quality.Contamination levels of multiple atmospheric pollutants were decreased.However,in this work,24 and 14 air fine particulate matter(PM_(2.5))samples were continuously collected before and during COVID-19 city lockdown in Linfen(a typical heavy industrial city in China),and intriguingly,the unreduced concentration was found for environmentally persistent free radicals(EPFRs)in PM_(2.5)after normal life suspension.The primary non-stopped coal combustion source and secondary Cu-related atmospheric reaction may have impacts on this phenomenon.The cigarette-based assessment model also indicated possible exposure risks of PM_(2.5)-bound EPFRs during lockdown of Linfen.This study revealed not all the contaminants in the atmosphere had an apparent concentration decrease during city lockdown,suggesting the pollutants with complicated sources and formation mechanisms,like EPFRs in PM_(2.5),still should not be ignored.

Supramolecular cyclization induced emission enhancement in a pillar[5]arene probe for discrimination of spermine

Early diagnosis and treatment of cancer requires the development of tools that are both sensitive and selective in detecting spermine.In this study,we presented a"supramolecular cyclization-induced emission enhancement"strategy for the sensitive and selective detection of spermine.A new pillar[5]arene probe(P1)demonstrated excellent solution/solid dual-state emission properties,and the addition of certain spermine(Spm)resulted in fluorescence enhancement due to the synergy of multiple weak interactions that restricted the free motion of P1 in the P1⊃Spm complex.This mechanism was further confirmed by time-resolved spectroscopy,DFT calculations,and IGM analysis.With its low limit of detection and high selectivity,P1 is a promising tool for measuring spermine in artificial urine samples.

A flexible pressure sensor with highly customizable sensitivity and linearity via positive design of microhierarchical structures with a hyperelastic model

The tactile pressure sensor is of great significance in flexible electronics,but sensitivity customization over the required working range with high linearity still remains a critical challenge.Despite numerous efforts to achieve high sensitivity and a wide working range,most sensitive microstructures tend to be obtained only by inverting naturally existing templates without rational design based on fundamental contact principles or models for piezoresistive pressure sensors.Here,a positive design strategy with a hyperelastic model and a Hertzian contact model for comparison was proposed to develop a flexible pressure sensor with highly customizable linear sensitivity and linearity,in which the microstructure distribution was precalculated according to the desired requirement prior to fabrication.As a proof of concept,three flexible pressure sensors exhibited sensitivities of 0.7,1.0,and 1.3 kPa−1 over a linear region of up to 200 kPa,with a low sensitivity error(<5%)and high linearity(~0.99),as expected.Based on the superior electromechanical performance of these sensors,potential applications in physiological signal recognition are demonstrated as well,and such a strategy could shed more light on demand-oriented scenarios,including designable working ranges and linear sensitivity for next-generation wearable devices.

Regulation of bimodal structure and mechanical properties of powder-thixoformed GO/ZK60 magnesium matrix composite through adjusting GO content

Although remarkable strength enhancements can be achieved in graphene oxide(GO)/graphene nanoplatelets(GNPs)reinforced Mg matrix composites by using the available techniques,their ductility is always quite poor due to the difficultly avoided strength-ductility trade-off.To conquer this dilemma,GO/ZK60 composites with bimodal-grain structure were fabricated using powder thixoforming in this work.The results indicate that the grain size and volume fraction of coarse grains(CGs)first decrease as the GO content increases to 0.2 wt.%and then increase again as the content increases to 0.3 wt.%,while the grain size in the fine grains(FGs)almost does not change.Consequently,the strength of the composites is improved with increasing GO content and reaches the peak values at the content of 0.2 wt.%.The composite with 0.1 wt.%GO content exhibits significantly increased tensile yield strength up to 177±2 MPa while maintaining a high elongation of 23.1%±2.5%,being equivalent to that of the ZK60 matrix alloy.The increased FGs volume fraction,together with the promoted dislocation accumulation and storage via GO and grain refinement of large-sized CGs lead to the improvement of strain hardening ability,thus rendering the composite an excellent ductility.Furthermore,the deformation of the GO/ZK60 composites occurs progressively from the FGs to the CGs,which is opposite to the status of the milled ZK60 matrix alloy.In view of the microstructure characteristics of the composites,a new complex calculation model was proposed and it could well predict the strength of the bimodal GO/ZK60 composites.This study provides a new insight into the microstructure design and fabrication technology of GO/GNPs reinforced metal-based composites with high strength and ductility.

Therapeutic effects of Chinese herbal medicines for treatment of urolithiasis: A review

Urolithiasis is a common and complex disease of the urinary system, which can cause urinary tract blockage, urinary tract infection, and even damage to urinary system-related tissues. Although urolithiasis can be cured, its high recurrence rate and the development of chronic kidney disease in some patients have drawn the attention of nephrologists. Although the application of extracorporeal lithotripsy, percutaneous nephrolithotomy and other minimally invasive techniques have made the treatment of urolithiasis more efficient, pharmacotherapy plays an indispensable role in reducing their morbidity and recurrence rates. Traditional Chinese medicine(TCM) has been used for treatment and prevention of urolithiasis in developing countries for centuries, known for its unquestionable efficacy and safety. This article reviews the progress of clinical trials and pharmacological studies on the treatment of urolithiasis with Chinese herbal medicines(CHMs). The mechanism of CHMs in the treatment of urolithiasis mainly involve preventing further growth and aggregation of urolithiasis, reducing the PH of urine, promoting calculus dissolution. Furthermore, some CHMs can increase urine output, relax smooth muscles, and promote the removal of calculus. These findings provide new treatment strategies and options for urolithiasis and secondary kidney damage.

Sulfur-promoted,one-pot,and metal-free conversion of aromatic aldehydes to nitriles using an inorganic ammonium salt as the nitrogen source

A simple protocol for the sulfur-promoted conversion of aromatic aldehydes to aromatic nitriles has been developed.This strategy enables the one-pot conversion of inexpensive and readily available aromatic aldehydes into highly valuable aromatic nitriles using a cheap inorganic ammonium salt as the nitrogen source in the absence of metals.Significantly,a broad scope of substrates was explored using this strategy,and various groups,including alkyl,alkoxyl,alkylthiol,hydroxyl,amino,aryl,alkenyl,cyano,carboxyl,and borate ester groups were tolerated,and good to excellent yields were achieved in most cases.Additionally,polycyclic aromatic aldehydes and heteroaromatic aldehydes also could be converted to the corre-sponding nitriles with satisfactory yields.This method can be utilized as a powerful tool for the cyanation of complex molecules.

高绩效工作系统对抑制性建言的影响研究:工会实践的调节作用

高绩效工作系统对抑制性建言的促进作用已得到证实,然而,其中的作用机制并未充分探讨。本文从资源保存理论出发,以情感承诺、心理安全为中介变量,工会实践为调节变量,探讨高绩效工作系统影响抑制性建言的内在机制,并以371名企业工会成员为样本,运用SPSS 22.0和Mplus 7.4进行统计检验。结果显示:(1)情感承诺和心理安全在高绩效工作系统与抑制性建言之间起中介作用;(2)工会实践正向调节了高绩效工作系统与情感承诺以及高绩效工作系统与心理安全之间的关系,进一步发现,工会实践水平越高,心理安全的中介作用越强,但工会实践对情感承诺的中介作用的影响并不显著。本文从资源保存理论的视角为激发员工抑制性建言提供了一个新的途径,同时也为促进工会实践与企业人力资源管理实践协同发展提供有力依据。

Nitrogen-doped fluorescence carbon dots as multi-mechanism detection for iodide and curcumin in biological and food samples

Iodine ion is one of the most indispensable anions in living organisms,particularly being an important substance for the synthesis of thyroid hormones.Curcumin is a yellow-orange polyphenol compound derived from the rhizome of Curcuma longa L.,which has been commonly used as a spice and natural coloring agent,food additives,cosmetics as well as Chinese medicine.However,excess curcumin may cause DNA inactivation,lead to a decrease in intracellular ATP levels,and trigger the tissue necrosis.Therefore,quantitative detection of iodine and curcumin is of great significance in the fields of food and life sciences.Herein,we develop nitrogen-doped fluorescent carbon dots(NCDs)as a multi-mechanism detection for iodide and curcumin in actual complex biological and food samples,which was prepared by a one-step solid-phase synthesis using tartaric acid and urea as precursors without adding any other reagents.An assembled NCDs-Hg^(2+) fluorescence-enhanced sensor for the quantitative detection of I^(-) was established based on a fluorescence“turn-off-on”mechanism in a linear range of 0.3-15μM with a detection limit of 69.4 nM and successfully quantified trace amounts of I^(-) in water samples and urine sample.Meanwhile,the as-synthesized NCDs also can be used as a fluorescent quenched sensor for curcumin detection based on the synergistic internal filtration effect(IFE)and static quenching,achieving a good linear range of 0.1-20μM with a satisfactory detection limit of 29.8 nM.These results indicate that carbon dots are potential sensing materials for iodine and curcumin detection for the good of our health.

Recent progress on flexible nanogenerators toward self-powered systems

The advances in wearable/flexible electronics have triggered tremendous demands for flexible power sources,where flexible nanogenerators,capable of converting mechanical energy into electricity,demonstrate its great potential.Here,recent progress on flexible nanogenerators for mechanical energy harvesting toward self-powered systems,including flexible piezoelectric and triboelectric nanogenerator,is reviewed.The emphasis is mainly on the basic working principle,the newly developed materials and structural design as well as associated typical applications for energy harvesting,sensing,and selfpowered systems.In addition,the progress of flexible hybrid nanogenerator in terms of its applications is also highlighted.Finally,the challenges and future perspectives toward flexible self-powered systems are reviewed.

Study of copper-cysteamine based X-ray induced photodynamic therapy and its effects on cancer cell proliferation and migration in a clinical mimic setting

Copper-cysteamine as a new generation of sensitizers can be activated by light,X-rays,microwaves,or ultrasound to produce reactive oxygen species.X-ray induced photodynamic therapy(X-PDT)has been studied extensively;however,most of the studies reported so far were conducted in the laboratory,which is not conducive to the clinical translation conditions.In this contribution,for the first time,we investigated the treatment efficiency of copper-cysteamine(Cu-Cy)based X-PDT by mimicking the clinical conditions with a clinical linear accelerator and building deep-seated tumor models to study not only the effectiveness but also its effects on the cell migration and proliferation in the level of the cell,tissue,and animal.The results showed that,without X-ray irradiation,Cu-Cy nanoparticles(NPs)had a low toxicity in HepG2,SK-HEP-1,Li-7,and 4T1 cells at a concentration below 100 mg/L.Interestingly,for the first time,it was observed that Cu-Cy mediated X-PDT can inhibit the proliferation and migration of these cell lines in a dose-dependent manner.Antigen markers of migration and cell proliferation,proliferating cell nuclear antigen(PCNA)and E-cadherin,from tumor tissue in the X-PDT group were remarkably different from that of the control group.Furthermore,the MRI assessment showed that the Cu-Cy based X-PDT inhibited the growth of deeply located tumors in mice and rabbits(p<0.05)without any obvious toxicities in vivo.Overall,these new findings demonstrate that Cu-Cy NPs have a safe and promising clinical application prospect in X-PDT to improve the efficiency of radiotherapy(RT)for deep-seated tumors and effectively inhibit tumor cell proliferation and migration.

A metal-electrode-free, fully integrated, soft triboelectric sensor array for self-powered tactile sensing

The dramatic advances in flexible/wearable electronics have garnered great attention for touch sensors for practical applications in human health monitoring and human–machine interfaces.Self-powered triboelectric tactile sensors with high sensitivity,reduced crosstalk,and simple processing routes are highly desirable.Herein,we introduce a facile and low-cost fabrication approach for a metal-electrode free,fully integrated,flexible,and self-powered triboelectric tactile sensor array with 8-by-8 sensor units.Through the height difference between the sensor units and interconnect electrodes,the crosstalk derived from the electrodes has been successfully suppressed with no additional shielding layers.The tactile sensor array shows a remarkable sensitivity of 0.063VkPa^(–1) with a linear range from 5 to 50kPa,which covers a broad range of testing objects.Furthermore,due to the advanced mechanical design,the flexible sensor array exhibits great capability of pressure sensing even under a curved state.The voltage responses from the pattern mapping by finger touching demonstrate the uniformity of the sensor array.Finally,real-time tactile sensing associated with light-emitting diode(LED)array lighting demonstrates the potential application of the sensor array in position tracking,self-powered touch screens,human–machine interfaces and many others.

Hexnut[12]arene and its derivatives: Synthesis, host-guest properties, and application as nonporous adaptive crystals

Hexnut[12]arene(HN[12])and its derivatives,a new class of sixfold macrocyclic arenes,were designed and synthesized in reasonable yield by a one-pot reaction at room temperature using dimethoxymethane as a methylene source.HN[12],which bears a large,symmetric,and rigid cavity,was easily functionalized at both the methylene bridges and the hydroquinone units.A water-soluble fluorescent HN[12]was synthesized and used as a host to encapsulate benzyl viologen dichloride in water with a high binding affinity of(3.4±0.2)×10^(6)M^(-1).The nonporous adaptive crystal(NAC)of HN[12]was found to capture not only inorganic molecules(iodine)but also trace amounts of large organic molecules(basic fuchsine)from water,which greatly expands the scope of NACs for adsorption.