Brassica species, including crops such as cabbage, turnip and oilseed, display enormous phenotypic variation. Brassica genomes have all undergone a whole-genome triplication (WGT) event with unknown effects on phenotype diversification. We resequenced 199 Brassica rapa and 119 Brassica oleracea accessions representing various morphotypes and identified signals of selection at the mesohexaploid subgenome level. For cabbage morphotypes with their typical leaf-heading trait, we identified four subgenome loci that show signs of parallel selection among subgenomes within B. rapa, as well as four such loci within B. oleracea. Fifteen subgenome loci are under selection and are shared by these two species. We also detected strong subgenome parallel selection linked to the domestication of the tuberous morphotypes, turnip (B. rapa) and kohlrabi (B. oleracea). Overall, we demonstrated that the mesohexaploidization of the two Brassica genomes contributed to their diversification into heading and tuber-forming morphotypes through convergent subgenome parallel selection of paralogous genes.

BrM/Ch LLP do not resemble plasma lipoproteins in density profile, cholesterol distribution, or morphology. Peak 2 contains EC-rich LLP resembling BrM particles in situ. BrM/Ch cholesteryl esters respond to long-term storage differently than esters of plasma lipoprotein origin accumulated in other ocular tissues. Evidence of intraocular apoB and apoA-I expression supports an emerging hypothesis that the RPE assembles and secretes a large, possibly novel, lipoprotein particle.

Nanocomposites have drawn a great interest in materials science of elastomers in recent years, and tailoring interfacial interactions between fillers and polymer matrix plays a critical role in improving their mechanical properties. The synthetic platform of tough and stretchable cellulose nanocrystal−poly(acrylamide) (CNC−PAM) composite hydrogels was proposed and applied here to unravel the role of covalent network in PAM and physical interactions by CNC surface adsorption. The attractive physical interactions in the network were considered to increase the fracture strength of the hydrogels via reversible adsorption−desorption processes on the CNC surface. Stress-sensitive characteristic shifts of the Raman peak located at 1095 cm −1 indicated an efficient load transfer across the interface, where the tensile modulus was higher than the compression modulus. In situ transmission electron microscopy observation allowed to demystify the composites deformation process and interfacial bridging between CNC and polymer matrix. A detailed comparison of strain rate effect on large strain dissipation indicated that the viscoelastic behavior of the hydrogels varied remarkably over strain rates, ranging from little hysteresis at low strain rates to highly dissipative at high strain rates, suggesting a new, slow relaxation mode, most likely due to interfacial adsorption of polymer chains on the CNC surfaces. This study showed that polymer chains desorbed from the CNC surface under periodic strains would entangle with the free chains after the rest time via conformational rearrangements, consequently triggering a recovering mechanism during multiple crazing and shear relaxation processes.

Carbon dots (CDs) as a new series of fluorescent nanomaterials have drawn great attention in recent years owning to their unique properties. In this paper, a simple carbonization approach to synthesize amino-functionalized CDs was developed by using chitosan as the carbon precursor. The as-prepared CDs possessed desirable amino function group on their surface and exhibited bright luminescence with absolute quantum yield (QY) of 4.34%, excitation-, pH-dependent and up-conversion fluorescence behaviors. Furthermore, we have investigated the cytotoxicity and biocompatibility of the as-prepared CDs, which demonstrated that the as-prepared CDs have the potential applications in biosensing, cellular imaging and drug delivery.

The principal extracellular lesions of age-related maculopathy (ARM), the leading cause of vision loss in the elderly, involve Bruch's membrane (BrM), a thin vascular intima between the retinal pigment epithelium (RPE) and its blood supply. With age, 80-100 nm solid particles containing esterified cholesterol (EC) accumulate in normal BrM, and apolipoprotein B (apoB) immunoreactivity is detectable in BrM-and ARM-associated lesions. Yet little evidence indicates that increased plasma cholesterol is a risk factor for ARM. To determine if RPE is capable of assembling its own apoB-containing lipoprotein, we examined RPE for the expression of microsomal triglyceride transfer protein (MTP), which is required for this process. Embryologically part of the central nervous system, the retina ( Fig. 1A ) converts light energy to electrochemical signals for transmission to the brain. The photoreceptors are supported by the retinal pigment epithelium (RPE), a monolayer with diverse functions including daily phagocytosis of the distal tips of photoreceptor outer segments (OS), and the choroid, a vascular bed with the body's highest blood flow. The choriocapillaris is a dense capillary plexus in the innermost choroid, and Bruch's membrane (BrM) is a thin vascular intima between the RPE and the choriocapillaris (Fig. 1B, arrowheads). In human retina, the macula subserves high-acuity vision and is vulnerable to age-related maculopathy (ARM), the major cause of vision loss among the elderly of industrialized societies. The most prominent histopathologic and clinical signs of ARM are extracellular lesions [drusen (Fig. 1E, F) and basal linear deposits (not shown)] in the RPE/BrM complex that ultimately impact vision by the photoreceptors (1, 2). Choroidal neovascularization, an invasion of choriocapillaries across BrM and lateral spread within the plane of drusen and basal linear deposit (see 3), is the principal sight-threatening complication of ARM's obscure underlying degeneration.Recent findings highlight a role for lipids and lipoproteins in this degeneration. These include a protective effect of the apolipoprotein E4 (apoE4) genotype in populations and the presence of apoB and apoE and histochemically identified lipids in aging-and ARM-associated drusen and deposits in human tissues (4-8) (Fig. 1E, F). The best established risk factor for early ARM is advanced age (9). A Abbreviations: ABL, abetalipoproteinemia; apoB, apolipoprotein B; apoBEC-1, apolipoprotein B-editing complex-1; ARM, age-related maculopathy; BrM, Bruch's membrane; EC, esterified cholesterol; ESI/MS, electrospray ionization mass spectrometry; INL, inner nuclear layer; MCT3, monocarboxylate transporter 3; MTP, microsomal triglyceride transfer protein; OS, outer segments of photoreceptors; RGC, retinal ganglion cell; RPE, retinal pigment epithelium; TC, total cholesterol; TG, triglyceride; UC, unesterified cholesterol.