Dowdhenriksen5048

In many species, leaves are initiated at the flanks of shoot meristems. Usually, subsequent growth mainly occurs in the plane of the leaf blade, which leads to the formation of a bifacial leaf with dorso-ventral identities. In a classical set of surgical experiments in potato meristems, Sussex provided evidence that dorsoventrality depends on a signal emanating from the meristem centre. Although these results could be reproduced in tomato, this concept has been debated. We revisited these experiments in Arabidopsis where a range of markers are available to target the precise site of ablation. Using specific markers for organ founder cells and dorsoventral identity, we were unable to perturb the polarity of leaves and sepals long before organ outgrowth. While results in Solanaceae suggested that dorsoventral patterning was unstable during early development, we find that in Arabidopsis the local information contained within and around the primordium is able to withstand major invasive perturbations, long before polarity is fully established.Peptides found in marine life have various specific activities due to their special growth environment, and there is increasing interest in the isolation and concentration of these biofunctional compounds. In this study, the protein hydrolysate of the marine worm Urechis unicinctus was prepared by enzymolysis and enriched by using mesoporous materials of silica MCM-41 and SBA-15 and carbon CMK-3. The differences in pore structures and elemental composition of these materials lead to differences in surface area and hydrophobicity. The adsorption capacities of peptides were 459.5 mg g-1, 431.3 mg g-1, and 626.3 mg g-1 for MCM-41, SBA-15 and CMK-3, respectively. Adsorption kinetics studies showed that the pseudo-second-order model fit the adsorption process better, where both external mass transfer and intraparticle diffusion affected the adsorption, while the Langmuir model better fit the adsorption of peptides on MCM-41 and SBA-15 and the Freundlich model was more suitable for CMK-3. Aqueous acetonitrile (ACN, 50/50, v/v) yielded the most extracted peptides. MALDI-TOF mass spectrometry of the extracted peptides showed that the three mesoporous materials, especially the CMK-3, gave good enrichment results. This study demonstrates the great potential of mesoporous materials in the enrichment of marine biofunctional peptides.Eye-drop formulations as conventional regimens to tackle ocular diseases are far from efficient due to the rapid clearance by eye tears and the blockage of the corneal epithelium barrier. Here, we describe a bioadhesive glycosylated nanoplatform with boric acid pendants as a drug carrier for noninvasive trans-corneal delivery of drugs to treat corneal neovascularization (CNV), a serious corneal disease resulting in significant vision impairment. This biocompatible nanoplatform is formulated from a synthetic amphiphilic boric acid-based copolymer self-assembling to form highly stable micelles with a high loading capacity for dexamethasone (DEX). The nanoplatform is demonstrated to be in contact with the corneal epithelium for a long period under the bioadhesive function of boric acid modules and releases the drug over 96 h in a controlled manner. Our results also suggest that the nanoplatform can be efficiently internalized by corneal epithelial cells in vitro and realize transcytosis in vivo to greatly enhance the transcorneal penetration of the loaded drugs into the pathological corneal stroma. On topical application against rat corneal alkali burn, the nanoformulation presents more robust efficacy on neovascularization suppression and inflammation elimination than free DEX with a negligible effect on normal tissues. This bioadhesive strategy which focuses on extending ocular drug retention and improving trans-corneal drug delivery not only highlights an approach for alternative noninvasive therapy of CNV but also provides a versatile paradigm for other biomedical applications by overcoming protective barriers.Herein, an efficient strategy is demonstrated to prepare a visible-light-driven Nb/Se co-doped BiOI photocatalyst with exposed (110) facets. The results show that its photocatalytic activity is around 17 times higher than that of pure BiOI. This work paves the way towards the fabrication of efficient photocatalysts that have tunable charge dynamics.Depression is closely related to overactivation of N-methyl-d-aspartic acid (NMDA) receptors, and Zn2+ is a vital NMDA receptor modulator involved in the pathophysiological and physiological processes of depression. Therefore, quantitative and real-time detection of Zn2+ is very important for understanding the pathogenesis of depression. In this work, a near-infrared (NIR) fluorescent probe ISO-DPA was designed and synthesized for Zn2+ detection with a large Stokes shift (185 nm), high quantum yield (up to 44%), high sensitivity (LOD = 0.106 μM) and good pH stability. The probe showed rapid response within 10 s, accompanied by a distinct fluorescence change from faint to bright pink with the fluorescence intensity increasing 4.5-fold. Moreover, the sensing mechanism of ISO-DPA towards Zn2+ was supported by MALDI-TOF-MS and Job's plot. The probe ISO-DPA could detect instantaneous variation of exogenous and endogenous Zn2+ in PC12 cells. The bioimaging results reveal the increase of the endogenous Zn2+ concentration in PC12 cells under the oxidative stress induced by glutamate and confirm that overactivation of NMDA receptors results in an increase of the Zn2+ level. All the results proved that ISO-DPA is an excellent probe for detecting Zn2+ in solution and living cells and could help us better understand Zn2+ associated pathogenesis of depression.The conformation and the electronic structure of gas-phase oligonucleotides depends strongly on the protonation site. Pilaralisib cell line 5'-d(FUAG) can either be protonated at the A-N1 or at the G-N7 position. We have stored protonated 5'-d(FUAG) cations in a cryogenic ion trap held at about 20 K. To identify the protonation site and the corresponding electronic structure, we have employed soft X-ray absorption spectroscopy at the nitrogen K-edge. The obtained spectra were interpreted by comparison to time-dependent density functional theory calculations using a short-range exchange correlation functional. Despite the fact that guanine has a significantly higher proton affinity than adenine, the agreement between experiment and theory is better for the A-N1 protonated system. Furthermore, an inverse site sensitivity is observed in which the yield of the nucleobase fragments that contain the absorption site appears substantially reduced, which could be explained by non-statistical fragmentation processes, localized on the photoabsorbing nucleobase.