HER2 Targeted Molecular MR Imaging Using a De Novo Designed Protein Contrast Agent

The application of magnetic resonance imaging (MRI) to non-invasively assess disease biomarkers has been hampered by the lack of desired contrast agents with high relaxivity, targeting capability, and optimized pharmacokinetics. We have developed a novel MR imaging probe targeting to HER2, a biomarker for various cancer types and a drug target for anti-cancer therapies. This multimodal HER20targeted MR imaging probe integrates a de novo designed protein contrast agent with a high affinity HER2 affibody and a near IR fluorescent dye. Our probe can differentially monitor tumors with different expression levels of HER2 in both human cell lines and xenograft mice models. In addition to its 100-fold higher dose efficiency compared to clinically approved non-targeting contrast agent DTPA, our developed agent also exhibits advantages in crossing the endothelial boundary, tissue distribution, and tumor tissue retention over reported contrast agents as demonstrated by even distribution of the imaging probe across the entire tumor mass. This contrast agent will provide a powerful tool for quantitative assessment of molecular markers, and improved resolution for diagnosis, prognosis and drug discovery

Mesoscopic-Functionalization of Silk Fibroin with Gold Nanoclusters Mediated by Keratin and Bioinspired Silk Synapse

2017年9月，厦门大学物理科学与技术学院刘向阳教授团队与河北大学闫小兵副教授团队合作, 在Small上发表此论文，第一次将功能化蚕丝用于制造阻变存储/神经元突触电子元件。这种蚕丝基生物仿生元器件, 可制成生物相容/可植入/可降解生物电子芯片, 在人工智领域以及生物医药方面，具有重要的应用前景。【Abstract】Silk fibroin (SF) offers great opportunities in manufacturing biocompatible/partially biodegradable devices with environmental benignity and biomedical applications. To obtain active SF devices of next generation, this work is to demonstrate a new functionalization strategy of the mesoscopic functionalization for soft materials. Unlike the atomic functionalization of solid materials, the meso-functionalization is to incorporate meso-dopants, i.e., functional molecules or nanomaterials, quantum dots, into the mesoscopic networks of soft materials. In this work, wool keratin (WK) molecules were adopted as mediating molecules to incorporate gold nanoclusters (AuNCs), into the mesoscopic networks of SF. It follows from our analyses that the β-crystallites between WK and SF molecules establish the binding between WK@AuNCs and the SF networks. The incorporated WK@AuNCs are electron rich and serve as electronically charged nano particles to bridge the growth of Ag filaments in bio-degradable WK@AuNCs–SF memristors. The meso-functionalization can greatly enhance the performance of SF materials and endows them with new functionalities. This can be highlighted by biocompatible/partly degradable WK@AuNCs functionalized SF resistive random-access memories, having the enhanced resistive switching memory performance, and the unique synapse characteristics and the capability of synapse learning compared with neat SF devices, and of great importance in nonvolatile memory, analog circuits, and neuromorphic applications.The work was supported by NUS tear 1 funding (WBS: R-144-000-367-112), the 111 Project (Grant No. B16029), National Natural Science Foundation of China (Grant Nos. 21404087 and 61674050, U1405226), Fujian Provincial Department of Science & Technology (Grant Nos. 2014H6022, 2015J05109), Natural Science Foundation of Guangdong Province (Grant No. 2015A030310007), 1000 Talents Program, and President Foundation from Xiamen University (Grant No. 20720160088), Ph. D. Programs Foundation of Ministry of Education of China (Grant No. 20130121110018). One of the authors, the primary affiliation of X.Y.L. is the Department of Physics, National University of Singapore. The authors are grateful to the China Scholarship Council (CSC) for the scholarship (Grant No. 201506630067) provided to one of the authors (Xing)

The spike weight contribution of the photosynthetic area above the upper internode in a winter wheat under different nitrogen and mulching regimes

Besides leaves, non-foliar green organs such as stem and spike are also considered photosynthetic organs. To assess the photosynthetic contributions of these organs, the correlations between these photosynthetic areas and single-spike weight were investigated in a winter wheat (Triticum aestivum L.) under four nitrogen and mulching treatments: N120, N150, N195, and N195 + M. Two-year repeated field experiments were conducted on the Loess Plateau of China. Non-foliar photosynthetic area, grain-filling ratio and duration, grain yield, and in particular, single-spike weight, were measured, recorded and analyzed. Under the N195 + M treatment, plants showed the largest area of photosynthetic organs (flag leaf and non-foliar organs) and the highest grain yield and single spike weight. Single-spike weight was positively correlated with the areas of all examined non-foliar photosynthetic organs, in particular with the area above the flag leaf node (R2 = 0.761⁎) and the area above the exposed part of the peduncle (EXP) (R2 = 0.800⁎⁎). In addition, single-spike weight was highly correlated with average grain-filling ratio (R2 = 0.993⁎⁎), whereas it was less highly correlated with grain-filling duration (R2 = 0.533). The morphological traits of non-foliar photosynthetic organs were also more highly correlated with average grain-filling ratio than with average grain-filling duration. The significant correlation between each of the morphological traits (area, length and width) of EXP and single-spike weight indicates that morphological traits of EXP are important in determining spike weight in the Loess Plateau environment. Keywords: Grain-filling ratio, Grain-filling duration, Loess Plateau, Photosynthetic organs, Single spike weight, Winter whea

Mapping of Ppd-B1, a Major Candidate Gene for Late Heading on Wild Emmer Chromosome Arm 2BS and Assessment of Its Interactions with Early Heading QTLs on 3AL.

Wheat heading date is an important agronomic trait determining maturation time and yield. A set of common wheat (Triticum aestivum var. Chinese Spring; CS)-wild emmer (T. turgidum L. subsp. dicoccoides (TDIC)) chromosome arm substitution lines (CASLs) was used to identify and allocate QTLs conferring late or early spike emergence by examining heading date. Genetic loci accelerating heading were found on TDIC chromosome arms 3AL and 7BS, while loci delaying heading were located on 4AL and 2BS. To map QTLs conferring late heading on 2BS, F2 populations derived from two cross combinations of CASL2BS × CS and CASL3AL × CASL2BS were developed and each planted at two times, constituting four F2 mapping populations. Heading date varied continuously among individuals of these four populations, suggesting quantitative characteristics. A genetic map of 2BS, consisting of 23 SSR and one single-stranded conformation polymorphism (SSCP) marker(s), was constructed using these F2 populations. This map spanned a genetic length of 53.2 cM with average marker density of 2.3 cM. The photoperiod-sensitivity gene Ppd-B1 was mapped to chromosome arm 2BS as a SSCP molecular marker, and was validated as tightly linked to a major QTL governing late heading of CASL2BS in all mapping populations. A significant dominance by additive effect of Ppd-B1 with the LUX gene located on 3AL was also detected. CS had more copies of Ppd-B1 than CASL2BS, implying that increased copy number could elevate the expression of Ppd-1 in CS, also increasing expression of LUX and FT genes and causing CS to have an earlier heading date than CASL2BS in long days

Preparation, microstructure and property of zinc-substituted hydroxyapatite/magnesium biocomposite

Zinc-substituted hydroxyapatite (Zn-HA, Ca10-xZnx(PO4)6(OH)2) is used as the modified material of hydroxyapatite (HA, Ca10 (PO4)6(OH)2). In this work, Zn-HA with Zn contents of 10-30 mol% was used to produce Zn-HA/Mg composites by powder metallurgy. The calculated results showed that the crystallite size and lattice parameters of Zn-HA powders varied with the contents of 0-30 mol% Zn, confirming that the divalent Zn2+ ions can substitute Ca2+ ions in HA. Furthermore, the microstructure, mechanical property and electrochemical corrosion behavior of Zn-HA/Mg composites were investigated by SEM, compression tests, and electrochemical corrosion tests, respectively. The results indicate that the highest density and lowest porosity are obtained and the optimal mechanical property and corrosion resistance are achieved in the Zn-HA/Mg composites with 20 mol% Zn