Search

The color of red-skinned pear (Pyrus spp.) is primarily attributed to accumulation of anthocyanins, which provide nutritional benefits for human health and are closely associated with the commercial value of fruits. Here, we reported the functional characterization of a R2R3-MYB repressor PyMYB107, which forms an 'activator-repressor' loop to control anthocyanin accumulation in the red-skinned pear. PyMYB107 overexpression inhibited anthocyanin biosynthesis in both pear calli and fruits, while virus-induced gene silencing of PyMYB107 increased anthocyanin accumulation in pear fruits. Furthermore, ectopic expression of PyMYB107 decreased anthocyanin accumulation in tomato, strawberry and tobacco. PyMYB107 can competitively bind to PybHLH3 with PyMYB10/MYB114, thereby suppressing the transcriptional activation of key anthocyanin biosynthesis genes, PyANS and PyUFGT. Site-directed mutagenesis showed that mutations within the R3 domain and EAR motif of PyMYB107 eliminated its repressive activity. Additionally, PyMYB107 exhibited a comparable expression pattern to PyMYB10/MYB114 and was transcriptionally activated by them. Our finding advanced comprehension of the repression mechanism underlying anthocyanin accumulation, providing valuable molecular insights into improving quality of pear fruits. [ABSTRACT FROM AUTHOR]

Tailorable chiral plasmonic nanostructures have attracted great interest due to their potential applications in photonics and sensing. However, there are limited straightforward fabrication routes to modulate the morphology of chiral materials with an external stimulus. Here, a helical assembly of gold nanospheres (AuNSs) is successfully obtained via self‐assembly using glycopeptide helical nanofibers as templates based on electrostatic interactions. The assembly morphology can be readily tailored from short debris to single‐/double‐ and multiple helical threads by changing pHs, resulting in well‐controlled modulation of circular dichroism (CD) in the visible range. Further, this tunable assembly and corresponding chiroptical properties are fully reversible in the pH range from 6 to 10. The electromagnetic simulation revealed how the structural geometries of AuNS helices changed the electromagnetic field propagation pattern to facilitate corresponding chiral optical properties. This approach is a unique and facilely obtained example of chiral nanomaterials with in situ tailoring morphology and chiral properties through external stimulus, demonstrating a potential application for biosensing. [ABSTRACT FROM AUTHOR]

Anthocyanins play a crucial role in imparting red coloration to pear fruits. However, the specific number and expression patterns of each member within the anthocyanin biosynthesis-related gene families in pears require systematic exploration. In this study, based on the pear genome we identified 15 gene families involved in the anthocyanin biosynthesis pathway using the BLASTP and Hidden Markov Model search methods, comprising a total of 94 enzyme genes. Through phylogenetic analysis, conserved domains, motif, and gene structure analysis, these gene families were further categorized into eight distinct lineages. Subsequent collinearity analysis revealed that the expansion of anthocyanin synthesis-related gene families primarily originated from segmental duplications. Analysis of cis-element in the promoter regions of genes related to anthocyanin synthesis unveiled the presence of light-responsive elements and various hormone-responsive elements. This suggests that changes in light stimulation and hormone levels may influence anthocyanin synthesis. RNA-Seq and qRT-PCR analyses indicated differential expression of anthocyanin biosynthesis-related genes between the peel and flesh tissues. During the accumulation of anthocyanins in red-fleshed pears, upstream genes in the anthocyanin biosynthesis pathway such as PbrPAL2, PbrC4H2, PbrC4H3, Pbr4CL2, Pbr4CL17, PbrF3H5, and PbrF3H6 exhibited high expression levels, likely contributing significantly to the red coloration of pear flesh. In summary, we have identified the number of gene family members involved in pear anthocyanin biosynthesis and analyzed the expression patterns of the genes related to pear anthocyanin biosynthesis. These findings provide a solid foundation for further research on the regulatory mechanisms underlying pear anthocyanin biosynthesis and the breeding of red pear varieties. [ABSTRACT FROM AUTHOR]

High speed,high mobility and high adaptability become the inevitable developing trend of quadruped robot,bionic joints as an important basis of moving parts,plays an important role about the kinematics and dynamics research of quadruped robot. Specific from four aspects of flexible pneumatic bionic joints,hydraulic damping bionic joints,series-wound elastic drive bionic joints and flexible variable stiffness bionic joints,the research status of quadruped robot bionic joints is summarized,and the various types of bionic joint defects are accurately analyzed. Finally,the future develop trend of quadruped bionic robot joints is described.With the deepening of the research,the quadruped robot bionic joint will have widely application prospect in production services,human exploration,future war and other special fields inevitably.

Although advances have been made in carbohydrate‐based macromolecular self‐assembly, harnessing epimers of carbohydrates to perform molecular assembly and further investigating the properties of supramolecular materials remain little explored. Herein, two classes of stereoisomeric glycolipid amphiphiles based on d‐N‐acetylgalactosamine (GalNAc) are reported, and they can aggregate into ribbon‐like structures in the aqueous solution due to amphiphilic property, which allow to obtain glycocalyx‐mimicking supramolecular materials. The subtle distinction in glycoside configuration of GalNAc‐α‐SSA and GalNAc‐β‐SSA dictates the different molecular packing in self‐assembled structures. Since driven by the distinguishing carbohydrate–carbohydrate interactions, the ribbon‐like architectures transform into spherical nanostructures via mixing GalNAc‐α‐SSA and GalNAc‐β‐SSA. The resulting spherical micelles fabricated by blending glycolipid epimers can potentiate the macrophage‐ and dendritic cell‐mediated immune responses in vitro. Such glycolipid epimers will pave the way to create glycocalyx‐mimicking immune modulators by incorporating stereochemistry into supramolecular self‐assembly. [ABSTRACT FROM AUTHOR]

The seismic amplitude along a layer in a section can reveal lateral reservoir changes and is one of the important means of reservoir prediction, but it is often difficult to establish the quantitative relationship between the seismic amplitude and sandstone thickness in wells in blocks with denser development. The use of a lower-amplitude slice for precisely quantitatively predicting the sandstone thickness, based on the goal of obtaining data on layers in the development zone with a dense well pattern, is accurate and has a valuable advantage. The method of formation slice optimization based on an objective function is studied to improve the ability of reservoir characterization by seismic attributes. This method has been applied to the reservoir prediction of the G I2 sedimentary unit in the ZQX block of the SRT oilfield and has achieved good results. [ABSTRACT FROM AUTHOR]

Background: Venetoclax (VEN) is the first selective small molecule Bcl-2 inhibitor approved by FDA and used in adult chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL) and some acute myeloid leukemia (AML). However, the long-term safety of VEN in large sample population was unknown. This study evaluated the adverse events (AEs) of VEN from FDA Adverse Event Reporting System (FAERS) since its approval in 2016 by data mining. Methods: The disproportionality analyses, including four algorithms of reporting odd ratio (ROR), proportional reporting ratio (PRR), bayesian configuration promotion neural network (BCPNN), and multi item gamma poisson shrinker (MGPS), were employed to quantify the signals of VEN-associated AEs. Results: From the FAERS database, a total of 8,379,682 reports were collected during the study period. After removing the duplication, the number of reports with VEN as the primary suspect (PS) was 19,107. The 19,107 cases of AEs involved 27 organ systems, 256 significant PTs which conforming to the four algorithms. Unexpected serious AEs, such as pleural effusion, splenic infarction, atrial fibrillation, skin squamous cell carcinoma, etc., have signals. The median time of occurrence of AEs related to VEN was 31 days (inter quartile range [IQR] 7–131 days), and half of the reported AEs occurred within 1 month after administration. Conclusion: Our research has found new significant AEs signals of VEN, which improved its safety information in real-world after marketing approval, and contributed to its risk control of use in clinic. [ABSTRACT FROM AUTHOR]

Magnetic core‐regular nanostructures composed of magnetite and regular Prussian blue was prepared by self‐sacrificial macro‐oriented method. Magnetic graphene oxide (MGO) was vertically oriented on the surface of home‐made screen‐printing electrode with the help of constant magnetic field (CMF).Then regular nanostructured Prussian blue (RPB) was realized by chemical reaction through an aerosol deposition. Finally, glucose oxidase (GOx) was immobilized by glutaraldehyde cross‐linking to fabricate glucose biosensors. The linear range of CMF‐RPB/MGO sensor towards glucose was 0.03∼1.35 mM, and the detection limit was 13.4 μM. The CMF‐RPB/MGO sensor could apply to analyze glucose in human serum samples. [ABSTRACT FROM AUTHOR]

Hierarchical porous tubular biochar (PTBC) was prepared by selectively removing lignin simply according to reverse the pyrolysis sequence of cellulose. The properties of the PTBC sample were characterized by XRD, SEM, TEM, Raman spectra, cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical performances of PTBC modified on the screen‐printing electrode illustrated excellent detection of lead ions (lead (II)) in water with the linear range (0.5–120 μg/L) and the detection limit (0.02 μg/L) by in‐situ bismuth film square wave anode stripping voltammetry. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: In recent years, synthesis of hybrid heteroarm star polymer with precisely defined arms has evolved to be one of the most attractive topics within polymer chemistry. In this study, we present the successful synthesis of metallacycle‐linked heteroarm star polymers (HASPs) composed of crystalline poly(ε‐caprolactone) (PCL) and polyacrylate (poly (N‐isopropylacrylamide) (PNIPAM) segments via combination of ring‐opening polymerization (ROP) and reversible addition‐fragmentation chain transfer (RAFT) controlled radical polymerization. Firstly, a hexagonal metallacycle containing three hydroxy groups and three chain transfer agent moieties at the alternative vertexes was designed and synthesized based on the general principle of coordination‐driven self‐assembly. Subsequently, upon combination of two orthogonal post‐assembly polymerizations, a new family of HASPs containing a well‐defined hexagonal metallacycle with precisely controlled position of polymer arms was facilely prepared. Interestingly, the obtained HASPs could spontaneously self‐assemble into large‐area and regular cubic nanoparticles in tetrahydrofuran (THF)/methanol (MeOH) mixed solvents under specific conditions as confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). This study provides a simple route to the controllable preparation of HASPs, and opens up a new way for further study on self‐assembly of different HASPs systems. [ABSTRACT FROM AUTHOR]