Isolation and characterization of putative functional long terminal repeat retrotransposons in the Pyrus genome

Annotation of 440 isolated LTR retrotransposons. (XLSX 88 kb

Roadmap on semiconductor-cell biointerfaces.

This roadmap outlines the role semiconductor-based materials play in understanding the complex biophysical dynamics at multiple length scales, as well as the design and implementation of next-generation electronic, optoelectronic, and mechanical devices for biointerfaces. The roadmap emphasizes the advantages of semiconductor building blocks in interfacing, monitoring, and manipulating the activity of biological components, and discusses the possibility of using active semiconductor-cell interfaces for discovering new signaling processes in the biological world

Nanowired human cardiac organoid transplantation enables highly efficient and effective recovery of infarcted hearts

Human cardiac organoids hold remarkable potential for cardiovascular disease modeling and human pluripotent stem cell–derived cardiomyocyte (hPSC-CM) transplantation. Here, we show cardiac organoids engineered with electrically conductive silicon nanowires (e-SiNWs) significantly enhance the therapeutic efficacy of hPSC-CMs to treat infarcted hearts. We first demonstrated the biocompatibility of e-SiNWs and their capacity to improve cardiac microtissue engraftment in healthy rat myocardium. Nanowired human cardiac organoids were then engineered with hPSC-CMs, nonmyocyte supporting cells, and e-SiNWs. Nonmyocyte supporting cells promoted greater ischemia tolerance of cardiac organoids, and e-SiNWs significantly improved electrical pacing capacity. After transplantation into ischemia/reperfusion–injured rat hearts, nanowired cardiac organoids significantly improved contractile development of engrafted hPSC-CMs, induced potent cardiac functional recovery, and reduced maladaptive left ventricular remodeling. Compared to contemporary studies with an identical injury model, greater functional recovery was achieved with a 20-fold lower dose of hPSC-CMs, revealing therapeutic synergy between conductive nanomaterials and human cardiac organoids for efficient heart repair

Periplasmic biomineralization for semi-artificial photosynthesis

Semiconductor-based biointerfaces are typically established either on the surface of the plasma membrane or within the cytoplasm. In Gram-negative bacteria, the periplasmic space, characterized by its confinement and the presence of numerous enzymes and peptidoglycans, offers additional opportunities for biomineralization, allowing for nongenetic modulation interfaces. We demonstrate semiconductor nanocluster precipitation containing single- and multiple-metal elements within the periplasm, as observed through various electron- and x-ray-based imaging techniques. The periplasmic semiconductors are metastable and display defect-dominant fluorescent properties. Unexpectedly, the defect-rich (i.e., the low-grade) semiconductor nanoclusters produced in situ can still increase adenosine triphosphate levels and malate production when coupled with photosensitization. We expand the sustainability levels of the biohybrid system to include reducing heavy metals at the primary level, building living bioreactors at the secondary level, and creating semi-artificial photosynthesis at the tertiary level. The biomineralization-enabled periplasmic biohybrids have the potential to serve as defect-tolerant platforms for diverse sustainable applications

Rational Design of Silicon Structures for Multi-Scale Biointerfaces

Silicon-based materials and devices represent a unique platform for interrogating fundamental biophysical processes. Recent advances in device designs and fabrications have enabled a wide variety of new silicon-based electronic and optoelectronic systems, which display multi-functional modalities that could be exploited for interfacing with various biological organizations. Besides the top-down fabrication which involves conventional lithographical processes, the bottom-up synthesis represents an alternative yet equally important method for the construction of silicon structures. In particular, the geometry and composition of the final construct can be tuned precisely during the materials growth, promising novel functions or applications beyond those offered by traditional platforms. In this thesis, I will report the design of a spectrum of silicon structures for the enhanced mechanical, electrical, and thermal biointerfaces, with targets spanning multiple length scales from nanoscopic organelles, microscopic single cells up to macroscopic tissues or organs. I will also focus on the study of fundamental aspects during the bottom-up synthesis to elucidate the underlying physicochemical processes that shape the silicon structures and properties. First, I will introduce a biocompatible and degradable mesostructured form of amorphous silicon with multiscale structural and chemical heterogeneities. I will also show that the heterogeneous silicon mesostructures can be used to design a lipid-bilayer-supported bioelectric interface that is remotely controlled and temporally transient, and that permits non-genetic and subcellular optical modulation of the electrophysiology dynamics in single dorsal root ganglia neurons. Secondly, I will demonstrate a biology-guided rational design principle for establishing intra-, inter- and extracellular silicon-based interfaces, where silicon and biological targets have matched properties. I will then demonstrate the utility of these interfaces by showing light-controlled non-genetic modulations of intracellular calcium dynamics, cytoskeleton-based transport and structures, cellular excitability, neural transmitter release from brain slices, and brain activities in vivo. Then, I will demonstrate an atomic-gold enabled three-dimensional (3-D) lithography for silicon mesostructures, by showing one example where iterated deposition-diffusion-incorporation of gold over silicon nanowires can produce mesostructured silicon spicules. In addition, I will show the anisotropic spicule has a strong interfacial interaction with the extracellular matrix, suggesting enhanced mechanical biointegrations. Finally, I will demonstrate that a liquid gold-silicon alloy established in classical vapor-liquid-solid growth can deposit ordered and three-dimensional rings of isolated gold atoms over silicon nanowire sidewalls. I will show that the single atomic gold-catalyzed chemical etching of silicon can lead to massive and ordered 3-D grooves on Si surfaces, which can serve as self-labelled and ex situ markers to resolve several complex silicon growths

Mechanical analysis of a flexible cable battery using the finite element model

Portable flexible electronic devices are receiving much attention for their flexible, portable, and wearable characteristics. The performance of such devices depends on the performance of the flexible battery to a great extent. The resistance of the battery is an important index of performance and a series of tests show that the resistance increases during deformation of the battery. In investigating how the mechanical behavior affects the resistance of the battery and optimizes the battery structure, a finite element model is developed to analyze the properties of the flexible-cable battery from a mechanical view. The model is used to analyze the mechanical behaviors of a wire-cable-type battery when the battery is solely subject to axial stretching, bending, or torsion. Effects of the cable lay angle and friction coefficient are considered. Effects of different loads on the resistance are presented considering the relationship between the strain and resistance. Simulation results show that the effect of the friction coefficient can be ignored. When the battery bears different loads, different lay angles are suggested for good flexibility and a small increase in resistance

Combined Analyses of Chloroplast DNA Haplotypes and Microsatellite Markers Reveal New Insights Into the Origin and Dissemination Route of Cultivated Pears Native to East Asia

Asian pear plays an important role in the world pear industry, accounting for over 70% of world total production volume. Commercial Asian pear production relies on four major pear cultivar groups, Japanese pear (JP), Chinese white pear (CWP), Chinese sand pear (CSP), and Ussurian pear (UP), but their origins remain controversial. We estimated the genetic diversity levels and structures in a large sample of existing local cultivars to investigate the origins of Asian pears using twenty-five genome-covering nuclear microsatellite (simple sequence repeats, nSSR) markers and two non-coding chloroplast DNA (cpDNA) regions (trnL-trnF and accD-psaI). High levels of genetic diversity were detected for both nSSRs (HE = 0.744) and cpDNAs (Hd = 0.792). The major variation was found within geographic populations of cultivated pear groups, demonstrating a close relationship among cultivar groups. CSPs showed a greater genetic diversity than CWPs and JPs, and lowest levels of genetic differentiation were detected among them. Phylogeographical analyses indicated that the CSP, CWP, and JP were derived from the same progenitor of Pyrus pyrifolia in China. A dissemination route of cultivated P. pyrifolia estimated by approximate Bayesian computation suggested that cultivated P. pyrifolia from the Middle Yangtze River Valley area contributed the major genetic resources to the cultivars, excluding those of southwestern China. Three major genetic groups of cultivated Pyrus pyrifolia were revealed using nSSRs and a Bayesian statistical inference: (a) JPs; (b) cultivars from South-Central China northward to northeastern China, covering the main pear production area in China; (c) cultivars from southwestern China to southeastern China, including Yunnan, Guizhou, Guangdong, Guangxi, and Fujian Provinces. This reflected the synergistic effects of ecogeographical factors and human selection during cultivar spread and improvement. The analyses indicated that UP cultivars might be originated from the interspecific hybridization of wild Pyrus ussuriensis with cultivated Pyrus pyrifolia. The combination of uniparental DNA sequences and nuclear markers give us a better understanding of origins and genetic relationships for Asian pear groups and will be beneficial for the future improvement of Asian pear cultivars

Discrete element analysis of deformation features of slope controlled by karst fissures under the mining effect: a case study of Pusa landslide, China

AbstractKarst landforms are widely distributed in the southwestern mountain areas of China, and the continuous underground mining activities lead to frequent occurrence of catastrophic collapses and landslides. Revealing the relationship between the development characteristics of the controlling karst fissures and the slope deformation process is crucial to understand the collapse and landslide phenomena. The Pusa landslide is selected as the geological prototype of discrete element analysis, and the universal distinct element code (UDEC) is applied to simulate the overall deformation response of the mountain containing extensive karst fissure during the mining process. The results show that under the action of mining, the roof above the goaf bends and subsides, and the middle of the roof even breaks and collapses. The separation fractures effectively block the upward transmission of the collapse state of the rock stratum. The bottom of the karst fissure is susceptible to cracking first in the process of coal seam mining due to stress concentration, and the area of severe deformation in the slope coincides with the mining pressurization area. The morphology of the karst fissure controls and determines the deformation characteristics of the rock mass at the slope top, and only the karst fissure located within the mining influence range is the object to be considered in the slope stability analysis. The limit karst fracture depth, about 1/3 of the slope height, is the limit value to determine whether the rock mass at the slope top is toppled or slipped. The relationship between the karst fissure and the free surface gradually changes from the directional or co-directional to the reverse, the motion state of the rock mass at the slope top changes from slipping to toppling, and the role of karst fissure changes from a potential slip surface to the cracking boundary. Although the deformation damage of the reverse structural slope is not very serious, the influence of the karst fissure on the stability of the slope still cannot be ignored. This study aims to provide basic theoretical support for the subsequent research on the failure mechanism of karst mountains under the combined action of multi-structural planes

Enhanced piezocatalytic performance of (Bi1/2Na1/2)(1-x)BaxTiO3 piezoelectric material with morphotropic phase boundary for degradation of RhB

Piezoelectric catalysis has been considered a promising technology in water pollution control. In this report, environmental-friendly (Bi1/2Na1/2)(1-x)BaxTiO3(BNBT-x) piezoelectric materials with the morphotropic phase boundary (MPB) were prepared by one-step solvothermal method. The piezocatalytic activities of the BNBT-x piezoelectric materials were examined by the degradation of RhB dye solution. The results demonstrate that the BNBT-6 catalyst with the MPB exhibit a higher piezocatalytic performance of up to 98.95% compared to pure BNT. In addition, the BNBT-6 catalyst exhibits good reusability, which is of great significance for practical applications. This work opens a route to design and develops high-performance piezocatalysts