A facile and efficient single-step approach for the fabrication of vancomycin functionalized polymer-based monolith as chiral stationary phase for nano-liquid chromatography

A facile single-step preparation strategy for fabricating vancomycin functionalized organic polymer based monolith within 100 mu m fused-silica capillary was developed. The synthetic chiral functional monomer, i.e 2-isocyanatoethyl methacrylate (ICNEML) derivative of vancomycin, was co-polymerized with the cross-linker ethylene dimethacrylate (EDMA) in the presence of methanol and dimethyl sulfoxide as the selected porogens. The co-polymerization conditions were systematically optimized in order to obtain satisfactory column performance. Adequate permeability, stability and column morphology were observed for the optimized poly(ICNEML-vancomycin-co-EDMA) monolith. A series of chiral drugs were evaluated on the monolith in either several other beta-blockers. The proposed single-step approach not only resulted in a vancomycin functionalized organer polar organic-phase or reversed-phase modes. After the optimization of separation conditions, baseline or partial enantioseparation were obtained for series of drugs including thalidomide, colchicine, carteolol, salbutamol, clenbuterol andic polymer-based monolith with acceptable performance, but also significantly simplified the preparation procedure by reducing time and labor

Sulfonated microporous polymer membranes with fast and selective ion transport for electrochemical energy conversion and storage

Membranes with fast and selective transport of protons and cations are required for a wide range of electrochemical energy conversion and storage devices, such as proton-exchange membrane (PEM) fuel cells and redox flow batteries. Here we report a new approach to designing solution-processable ion-selective polymer membranes with both intrinsic microporosity and ion-conductive functionality. This was achieved by synthesizing polymers with rigid and contorted backbones, which incorporate hydrophobic fluorinated and hydrophilic sulfonic acid functional groups, to produce membranes with negatively-charged subnanometer-sized confined ionic channels. The facilitated transport of protons and cations through these membranes, as well as high selectivity towards nanometer-sized redox-active molecules, enable efficient and stable operation of an aqueous alkaline quinone redox flow battery and a hydrogen PEM fuel cell. This membrane design strategy paves the way for producing a new-generation of ion-exchange membranes for electrochemical energy conversion and storage applications

On <i>r</i>-Regular Integers (mod <i>n</i>^r)

Let ρr(nr) denote the number of positive r-regular integers (modnr) that are less than or equal to nr; in this paper, we investigate some arithmetic properties of certain functions related to r-regular integers (modnr). Then, we study the average orders and the extremal orders of ρr(nr) in connection with the divisor function and the generalized Dedekind function. Moreover, we also introduce an analogue of Cohen–Ramanujan’s sum with respect to r-regular integers (modnr) and show some basic properties of this function

Mean Value of <i>r</i>-gcd-sum and <i>r</i>-lcm-Sum Functions

In this paper we perform a further investigation for r-gcd-sum and r-lcm-sum functions. By making use of the properties of generalization of Euler’s φ-function, Abel’s identity and elementary arguments, we derive asymptotic formulas for the average of the r-gcd-sum function, r-lcm-sum function and their generalizations. Moreover, we also study the sums of reciprocals of r-gcd and r-lcm

Multiple areas investigation reveals the genes related to vascular bundles in rice

Abstract Background The vascular bundle in the panicle neck is a crucial trait in rice (Oryza sativa) production that differs between the indica and japonica subspecies. However, the effect of indica/japonica genetic background on the vascular bundles remains unknown. Results A series of recombinant inbred lines (RILs) derived from a cross between japonica and indica were planted in three areas. High-throughput sequencing was conducted to determine the indica pedigree percentage and for quantitative trait locus (QTL) analysis. The indica pedigree affected the number of large vascular bundles (LVBs), but not the number of small vascular bundles (SVBs). QTL analysis identified a locus (qLVB9) that was pleiotropic for both LVBs and SVBs in all three areas, and qLVB9 appeared synonymous with DENSE AND ERECT PANICLE 1 (DEP1). Using CRISPR/Cas9 gene editing and gene overexpression technology, we confirmed that the truncated dep1 allele increased the number of LVBs, and resulted in LVBs more closely associated to the indica pedigree. RNA sequencing showed that the truncated dep1 allele downregulated the AP2-like gene family. The double mutant for the DEP1 and AP2-like genes (OsAP2–39) showed decreased endogenous abscisic acid (ABA) level and insensitivity to exogenous ABA treatment, confirming that both DEP1 and OsAP2–39 are involved in the ABA response mechanism. Conclusions The present study showed the qLVB9/DEP1 affects LVBs, and involved in ABA signaling via regulating the AP2-like gene family. These results offer new insights into the function of qLVB9/DEP1 in rice

Introgression of a Complex Genomic Structural Variation Causes Hybrid Male Sterility in <i>GJ</i> Rice (<i>Oryza sativa</i> L.) Subspecies

Hybrids between different subspecies of rice Oryza sativa L. commonly show hybrid sterility. Here we show that a widely planted commercial japonica/GJ variety, DHX2, exhibited hybrid sterility when crossing with other GJ varieties. Using the high-quality genome assembly, we identified three copies of the Sc gene in DHX2, whereas Nipponbare (Nip) had only one copy of Sc. Knocking out the extra copies of Sc in DHX2 significantly improved the pollen fertility of the F1 plant of DHX2/Nip cross. The population structure analysis revealed that a slight introgression from Basmati1 might occur in the genome of DHX2. We demonstrated that both DHX2 and Basmati1 harbored three copies of Sc. Moreover, the introgression of GS3 and BADH2/fgr from Basmati1 confers the slender and fragrance grain of DHX2. These results add to our understanding of the hybrid sterility of inter-subspecies and intra-subspecies and may provide a novel strategy for hybrid breeding