Tri-state logic computation by activating DNA origami chains.

The invention of DNA nanotechnology has enabled molecular computation as a promising substitute for traditional semiconductors which are limited to two-dimensional architectures and by heating problems resulting from densification. Current studies of logic gates achieved using DNA molecules are predominately focused on two-state operations (AND, OR, .); however, realizing tri-state logic (high impedance Z) in DNA computation is understudied.

Non-equilibrium structural and dynamic behaviors of active polymers in complex and crowded environments.

Active matter systems, which convert internal chemical energy or energy from the environment into directed motion, are ubiquitous in nature and exhibit a range of emerging non-equilibrium behaviors. However, most of the current works on active matter have been devoted to particles, and the study of active polymers has only recently come into the spotlight due to their prevalence within living organisms. The intricate interplay between activity and conformational degrees of freedom gives rise to novel structural and dynamical behaviors of active polymers.

[A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020].

Objectives: To investigate the clinical characteristics and prognosis of pneumococcal meningitis (PM), and drug sensitivity of (SP) isolates in Chinese children.

Methods: A retrospective analysis was conducted on clinical information, laboratory data, and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.

Results: Among the 160 children with PM, there were 103 males and 57 females.

Effects of stable and fluctuating soil water on the agronomic and biological performance of root vegetables.

Compared to fluctuating soil water (FW) conditions, stable soil water (SW) can increase plant water use efficiency (WUE) and improve crop growth and aboveground yield. It is unknown, however, how stable and fluctuating soil water affect root vegetables. Here, the effects of SW and FW were studied on cherry radish in a pot experiment, using negative pressure irrigation and conventional irrigation, respectively.

Programmable Potentials Choreograph Defects in a Colloidal Crystal Shell.

Crystallization on spherical surfaces is obliged by topology to induce lattice defects. But controlling the organization of such defects remains a great challenge due to the long-range constraints of the curved geometry. Here, we report on DNA-coated colloids whose programmable interaction potentials can be used to regulate the arrangement of defects and even achieve perfect icosahedral order on a sphere.

Toward three-dimensional DNA industrial nanorobots.

Nanoscale industrial robots have potential as manufacturing platforms and are capable of automatically performing repetitive tasks to handle and produce nanomaterials with consistent precision and accuracy. We demonstrate a DNA industrial nanorobot that fabricates a three-dimensional (3D), optically active chiral structure from optically inactive parts. By making use of externally controlled temperature and ultraviolet (UV) light, our programmable robot, ~100 nanometers in size, grabs different parts, positions and aligns them so that they can be welded, releases the construct, and returns to its original configuration ready for its next operation.

Atherosclerosis indexes and incident T2DM in middle-aged and older adults: evidence from a cohort study.

Background: Type 2 diabetes mellitus (T2DM) is an expanding global health problem, requiring effective methods for predicting and diagnosing in its early stages of development. Previous studies reported the prognostic value of the atherosclerosis indexes in both cardiovascular diseases and T2DM. However, the predictive performance of Non-HDL-C, AI, AIP, TG/HDL-C and LCI indexes on the risk of T2DM remains unclear.

Stable Soil Moisture Improves the Water Use Efficiency of Maize by Alleviating Short-Term Soil Water Stress.

Weaker temporal variation of soil moisture can improve crop water use efficiency (WUE), but its physiological mechanism was still unclear. To explore the mechanism, an organized experiment was conducted in Beijing from June to September. From the jointing stage to maturity stage of maize, stable soil moisture (SSM) and fluctuating soil moisture (FSM) were established with Pressure Potential Difference-Crop Initiate Drawing Water (PCI) and manual irrigation (MI), respectively, to explore the physiological mechanism of SSM to improve maize WUE.

Divalent Multilinking Bonds Control Growth and Morphology of Nanopolymers.

Assembly of nanoscale objects into linear architectures resembling molecular polymers is a basic organization resulting from divalent interactions. Such linear architectures occur for particles with two binding patches on opposite sides, known as Janus particles. However, unlike molecular systems where valence bonds can be envisioned as pointlike interactions nanoscale patches are often realized through multiple molecular linkages.

Report on the 19th international symposium on geo-disaster reduction/high-level academic forum on disaster mitigation and integrated risk defense on the Plateau, 12-15 July 2021, Xining, China.

The joint event of 19th International Symposium on Geo-disaster Reduction (19ISGdR) and High-Level Academic Forum on Disaster Mitigation and Integrated Risk Defense on the Plateau was held on 11-15 July in Xining, Qinghai Province, China, focusing on the theme of "Geological disaster and integrated risk defense". This event consisted of keynote lectures, invited lectures, and Youth forum, which provided a platform for scientists, industrial professionals and young scholars to share their research progress and exchange novel ideas on geo-disaster reduction in a hybrid way of offline and online. A post-symposium field trip for three days was also conducted in the joint area between Qinghai-Tibet plateau and Loess plateau.

Entropy-Driven Unconventional Crystallization of Spherical Colloidal Nanocrystals Confined in Wide Cylinders.

The densest packings of identical spherical colloidal nanocrystals in a thin cylinder generally give rise to confinement-induced chiral ordering. Here, we demonstrate that entropy can invalidate Pauling's packing rules for the nanocrystals confined in wide cylinders and novel ordered phases, where chiral ordering is broken, emerge. The nucleation and growth of spherical colloidal nanocrystals in the wide cylinders exhibit unique mechanisms which are distinctly different from that of thin ones.

Microchemomechanical devices using DNA hybridization.

The programmability of DNA oligonucleotides has led to sophisticated DNA nanotechnology and considerable research on DNA nanomachines powered by DNA hybridization. Here, we investigate an extension of this technology to the micrometer-colloidal scale, in which observations and measurements can be made in real time/space using optical microscopy and holographic optical tweezers. We use semirigid DNA origami structures, hinges with mechanical advantage, self-assembled into a nine-hinge, accordion-like chemomechanical device, with one end anchored to a substrate and a colloidal bead attached to the other end.

Entropy at Bio-Nano Interfaces.

Entropy, one of the central concepts of thermodynamics, can be a predominant contribution to structural formation and transition. Although it is well-known that diverse forces and energies can significantly contribute to the structures and activities at bio-nano interfaces, the potential entropic contribution remains less well understood. Therefore, this review article seeks to provide a conceptual framework demonstrating that entropy can be exploited to shape the physicochemical properties of bio-nano interfaces and thereby regulate the structures, responses, and functions of biological systems.

Cellular Uptake of Active Particles.

Active particles are widely recognized to potentially revolutionize technologies in numerous biomedical applications. However, the physical origin behind cellular uptake of these particles in the nonequilibrium state remains scarcely understood. Here we combine Brownian dynamics simulation as well as theoretical analysis to provide the criterion for cellular uptake of active particles, related to various physical attributes.

Entropy-Mediated Mechanomutable Microstructures and Mechanoresponsive Thermal Transport of Nanoparticle Self-Assembly in Block Copolymers.

Despite decades of intense research efforts on the self-assembly of nanoparticles in mesophase-forming copolymers, the progress in practical applications is impeded by the lack of knowledge about the dynamic transition of such hierarchical nanostructures in an environment bearing an external load. Here, we show that the hierarchical self-assembly of nanoparticles in block copolymer scaffolds can be made to significantly alternate by external compression, characterized by a continuous and reverse transition among various distribution states of nanoparticles in their preferential domains. Theoretical analysis reveals that compression-induced transition of the nanoparticle distribution can be fundamentally attributed to unique entropic effects originating from the compacted block chains.

Optimal ligand-receptor binding for highly efficient capture of vesicles in nanofluidic transportation.

Optimizing ligand-receptor binding is essential for exploiting advanced biomedical applications from targeting drug delivery to biosensing. A key challenge is how optimized ligand-receptor binding can be realized during the transport of ligand-modified soft materials through a nanofluidic channel. Here, by combining computer simulations and theoretical analysis, we report that the ligand-receptor binding and resulting capture probability of ligand-functionalized vesicles nonmonotonically depend on their some intrinsic properties, e.

Plastic Crystal-to-Crystal Transition of Janus Particles under Shear.

Colloidal Janus spheres in the bulk typically spontaneously assemble into plastic crystalline phases, while particle orientations exhibit glasslike dynamics without long-range order. Through Brownian dynamics simulations, we demonstrate that shear can trigger a phase transition from an isotropic crystal with orientational disorder to an orientationally ordered crystal with lamellae along the shear direction. This nonequilibrium transition is accompanied with the orientational ordering following a nucleation and growth mechanism.

Entropic Effects in Polymer Nanocomposites.

Polymer nanocomposite materials, consisting of a polymer matrix embedded with nanoscale fillers or additives that reinforce the inherent properties of the matrix polymer, play a key role in many industrial applications. Understanding of the relation between thermodynamic interactions and macroscopic morphologies of the composites allow for the optimization of design and mechanical processing. This review article summarizes the recent advancement in various aspects of entropic effects in polymer nanocomposites, and highlights molecular methods used to perform numerical simulations, morphologies and phase behaviors of polymer matrices and fillers, and characteristic parameters that significantly correlate with entropic interactions in polymer nanocomposites.

Hierarchical Crystals Formed from DNA-Functionalized Janus Nanoparticles.

Harnessing anisotropic interactions in a DNA-mediated nanoparticle assembly holds great promise as a rational strategy to advance this important area. Here, using molecular dynamics simulations, we report the formation of novel hierarchical crystalline assemblies of Janus nanoparticles functionalized with two types of DNA chains (DNA-JNPs). We find that in addition to the primary nanoparticle crystallization into face-centered cubic (FCC) structure, sequence-specific DNA hybridization events further direct the rotational orientation of the DNA-JNPs to diverse secondary crystalline phases including simple cubic (SC), tetragonally ordered cylinder (P4), and lamella (L) structures, which are mapped in the phase diagrams relating to various asymmetric parameters.

How Implementation of Entropy in Driving Structural Ordering of Nanoparticles Relates to Assembly Kinetics: Insight into Reaction-Induced Interfacial Assembly of Janus Nanoparticles.

The ability to understand and exploit entropic contributions to ordering transition is of essential importance in the design of self-assembling systems with well-controlled structures. However, much less is known about the role of assembly kinetics in entropy-driven phase behaviors. Here, by combining computer simulations and theoretical analysis, we report that the implementation of entropy in driving phase transition significantly depends on the kinetic process in the reaction-induced self-assembly of newly designed nanoparticle systems.

Bacteria-Activated Janus Particles Driven by Chemotaxis.

In the development of biocompatible nano-/micromotors for drug and cargo delivery, motile bacteria represent an excellent energy source for biomedical applications. Despite intense research of the fabrication of bacteria-based motors, how to effectively utilize the instinctive responses of bacteria to environmental stimuli in the fabrication process, particularly, chemotaxis, remains an urgent and critical issue. Here, by developing a molecular-dynamics model of bacterial chemotaxis, we present an investigation of the transport of a bacteria-activated Janus particle driven by chemotaxis.

Tailoring Interfacial Nanoparticle Organization through Entropy.

The ability to tailor the interfacial behaviors of nanoparticles (NPs) is crucial not only for the design of novel nanostructured materials with superior properties and of interest for many promising applications such as water purification, enhanced oil recovery, and innovative energy transduction, but also for a better insight into many biological systems where nanoscale particles such as proteins or viruses can interact and organize at certain interfaces. As a class of emerging building blocks, Janus NPs consisting of two compartments of different chemistry or polarity are ideal candidates to generate tunable and stable interfacial nanostructures because of the asymmetric nature. However, precise control over such interfacial nanostructures toward a controllable order and even responses to various external stimuli still remains a great challenge as the interfaces do not simply serve as a scaffold but rather induce complex enthalpic and entropic interactions.

Mesoscale Graphene-like Honeycomb Mono- and Multilayers Constructed via Self-Assembly of Coclusters.

Honeycomb structure endows graphene with extraordinary properties. But could a honeycomb monolayer superlattice also be generated via self-assembly of colloids or nanoparticles? Here we report the construction of mono- and multilayer molecular films with honeycomb structure that can be regarded as self-assembled artificial graphene (SAAG). We construct fan-shaped molecular building blocks by covalently connecting two kinds of clusters, one polyoxometalate and four polyhedral oligomeric silsesquioxanes.

[Pharmacokinetics of α-asarone after intranasal and intravenous administration with PLA-α-asarone nanoparticles].

PLA-α-asarone nanoparticles were prepared by using organic solvent evaporation method, and their in vivo distribution and brain targeting after intranasal administration were studied as compared with intravenous administration. The results showed that brain targeting coefficient of PLA-α-asarone nanoparticles after intranasal and intravenous administration was 1.65 and 1.