Digital Data Storage Using DNA Nanostructures and Solid-State Nanopores.

Solid-state nanopores are powerful tools for reading the three-dimensional shape of molecules, allowing for the translation of molecular structure information into electric signals. Here, we show a high-resolution integrated nanopore system for identifying DNA nanostructures that has the capability of distinguishing attached short DNA hairpins with only a stem length difference of 8 bp along a DNA double strand named the DNA carrier. Using our platform, we can read up to 112 DNA hairpins with a separating distance of 114 bp attached on a DNA carrier that carries digital information. Our encoding strategy allows for the creation of a library of molecules with a size of up to 5 × 1033 (2112) that is only built from a few hundred types of base molecules for data storage and has the potential to be extended by linking multiple DNA carriers. Our platform provides a nanopore- and DNA nanostructure-based data storage method with convenient access and the potential for miniature-scale integration

Ionic conductivity, structural deformation, and programmable anisotropy of DNA origami in electric field.

The DNA origami technique can enable functionalization of inorganic structures for single-molecule electric current recordings. Experiments have shown that several layers of DNA molecules, a DNA origami plate, placed on top of a solid-state nanopore is permeable to ions. Here, we report a comprehensive characterization of the ionic conductivity of DNA origami plates by means of all-atom molecular dynamics (MD) simulations and nanocapillary electric current recordings. Using the MD method, we characterize the ionic conductivity of several origami constructs, revealing the local distribution of ions, the distribution of the electrostatic potential and contribution of different molecular species to the current. The simulations determine the dependence of the ionic conductivity on the applied voltage, the number of DNA layers, the nucleotide content and the lattice type of the plates. We demonstrate that increasing the concentration of Mg(2+) ions makes the origami plates more compact, reducing their conductivity. The conductance of a DNA origami plate on top of a solid-state nanopore is determined by the two competing effects: bending of the DNA origami plate that reduces the current and separation of the DNA origami layers that increases the current. The latter is produced by the electro-osmotic flow and is reversible at the time scale of a hundred nanoseconds. The conductance of a DNA origami object is found to depend on its orientation, reaching maximum when the electric field aligns with the direction of the DNA helices. Our work demonstrates feasibility of programming the electrical properties of a self-assembled nanoscale object using DNA.C.Y.L., J.Y. and A.A. were supported in part by the grants from the National Science Foundation (DMR-0955959, PHY-1430124 and ECC-1227034), and the National Institutes of Health (R01- HG007406). E.A.H. acknowledges support from Schweizerische Studienstiftung (Swiss Study Foundation) and Gonville & Caius College. S.H.A. acknowledges support from a Herchel Smith postdoctoral fellowship. J.K. acknowledges support from Chinese Scholarship Council and Cambridge Overseas Trust. UFK was supported by an ERC starting grant (PassMembrane, 261101). The authors gladly acknowledge supercomputer time provided through XSEDE Allocation Grant MCA05S028 and the Blue Waters Sustained Petascale Computer System (UIUC).This is the accepted manuscript. The final version is available from ACS at pubs.acs.org/doi/abs/10.1021/nn505825z

Cryosphere Services to Support SDGs in High Mountains

The cryosphere is able to provide a variety of services for the benefit of human well-being and underpins regional sustainable development. The cryosphere deterioration induced by climate change is impacting the services and will subsequently impede the efforts to meet sustainable development goals (SDGs) in high mountain societies. Here, we detail the context of cryosphere services and establish a dataset for its linkage to SDGs. This allows us to uncover its roles in supporting SDGs, directly by a causal connection and indirectly through either cascading effects or interconnection among SDGs. We find that the SDGs in association with the basic needs of high mountain societies are mostly affected by the cryosphere services. The different types of services pitch in with distinctions to be embraced by various SDGs, whilst some play a prominent role in the contribution to a broad range of SDGs. We further investigate how the services behave in their contributions to SDGs, by taking a view via the lens of a network that deciphers the relationship between the services and SDG targets as well as the interconnections among SDG targets. With an insight into the centrality and modularity of services in the network, we then delineate the inherent criticality of services to SDG targets as a whole, and reveal the specificity of services that co-contribute to a cluster of SDG targets in each network community. We take out the services from the network and maintain their interlinks to the targets of each underlying SDG system represented in six key entry points, so that the services critical to the transformation pathways in the entry points for SDGs in high mountains can be identified. Finally, we discuss the trade-offs that can occur in high mountains, which is unique for the cryosphere services. It creates more complexity in the assessment of overall benefits that the cryosphere services may provide to SDGs, and urges the balance that has to be maintained in attaining those services for the transformation

Spatial and Temporal Evolution and Driving Mechanisms of Water Conservation Amount of Major Ecosystems in Typical Watersheds in Subtropical China

The water conservation function of ecosystems is a research hot spot in the field of water resources, and it is also an important ecological service function of terrestrial ecosystems and a key point in eco-hydrology research. With the increasing frequency of human activities and climate change, how to reveal the response of ecosystem water conservation function to the changing environment is a scientific problem that needs to be urgently addressed in ecological hydrology research. To reveal the eco-hydrological processes under the changing environment, this study was based on the distributed hydrological model (SWAT) and used water conservation amount (WCA) as an indicator to assess the water conservation capacity of ecosystems. Scenario analysis and statistical analysis were also used to determine the spatial and temporal evolution of the WCAs of farmland, forest, and grassland ecosystems under a changing environment and to further investigate the influence mechanisms of land use change and climate change on the WCA. The findings show that (1) the climate conditions in the Hanjiang watershed have determined the distribution pattern of the ecosystem’s WCA. The spatial distribution patterns of the WCA of each ecosystem differed significantly between the dry season and the wet season. Under the combined influence of human activities and climate change, there was no significant change in the spatial distribution pattern of the WCA. (2) Climate change patterns, which were dominated by precipitation and influenced by evapotranspiration, determined the changes in the WCA of ecosystems. In addition, there were significant spatial differences in the response of the watershed WCA under changing environments in the dry season. Differences in land use type and local climate change were the main reasons for such differences. (3) There were differences in the WCA and the response to changing environments among ecosystems. Forest ecosystems had the highest WCA; grassland ecosystems were the most sensitive to land use change. This study can provide a theoretical basis for alleviating the increasingly serious water resource problems in the basin and ensuring water and ecological security in the basin

Cryosphere Services to Support SDGs in High Mountains

The cryosphere is able to provide a variety of services for the benefit of human well-being and underpins regional sustainable development. The cryosphere deterioration induced by climate change is impacting the services and will subsequently impede the efforts to meet sustainable development goals (SDGs) in high mountain societies. Here, we detail the context of cryosphere services and establish a dataset for its linkage to SDGs. This allows us to uncover its roles in supporting SDGs, directly by a causal connection and indirectly through either cascading effects or interconnection among SDGs. We find that the SDGs in association with the basic needs of high mountain societies are mostly affected by the cryosphere services. The different types of services pitch in with distinctions to be embraced by various SDGs, whilst some play a prominent role in the contribution to a broad range of SDGs. We further investigate how the services behave in their contributions to SDGs, by taking a view via the lens of a network that deciphers the relationship between the services and SDG targets as well as the interconnections among SDG targets. With an insight into the centrality and modularity of services in the network, we then delineate the inherent criticality of services to SDG targets as a whole, and reveal the specificity of services that co-contribute to a cluster of SDG targets in each network community. We take out the services from the network and maintain their interlinks to the targets of each underlying SDG system represented in six key entry points, so that the services critical to the transformation pathways in the entry points for SDGs in high mountains can be identified. Finally, we discuss the trade-offs that can occur in high mountains, which is unique for the cryosphere services. It creates more complexity in the assessment of overall benefits that the cryosphere services may provide to SDGs, and urges the balance that has to be maintained in attaining those services for the transformation

Celery‐derived scaffolds with liver lobule‐mimicking structures for tissue engineering transplantation

Abstract Decellularized scaffolds have a demonstrated value in liver tissue engineering. Challenges in this area are focused on effectively eliminating the biological rejection of scaffolds and finding a suitable liver cell source. Here, inspired by the natural microstructure of hepatic lobules, we present a novel decellularized celery‐derived scaffold cultured with human‐induced pluripotent stem cell‐derived hepatocytes (hiPSC‐Heps) bioengineering liver tissue construction. Because of the natural hollow channels, interconnected porous structures, and excellent physicochemical characterization of the decellularized celery‐derived scaffold, the resultant bioengineering liver tissue can maintain the hiPSC‐Heps viability and the hepatic functions in the in vitro cultures. Based on this bioengineering liver tissue, we have demonstrated its good biocompatibility and the significantly higher expressions of albumin (ALB) and periodic acid‐schiff stain (PAS) when it was implanted in nude mice. These remarkable properties endow the hiPSC‐Heps integrated decellularized celery scaffolds system with promising prospects in the field of liver transplantation and other regeneration medicine

Cryosphere Services to Advance the National SDG Priorities in Himalaya-Karakoram Region

The cryosphere in the Himalaya-Karakoram (H-K) is widespread, and its services significantly affect the SDGs implementation in the region, in particular related to the ‘No poverty’ (SDG 1), ‘zero hunger’ (SDG 2), ‘good health and well-being’ (SDG 3), ‘work and economic’ (SDG 8) and ‘partnership for the goals’ (SDG 17). We here established the networks to illustrate the complex relationship of cryosphere services with national SDG priorities in the countries of H-K, including Afghanistan, Pakistan, India, China, Nepal and Bhutan. The cryosphere services contributing to the national SDG priorities and the key targets were elucidated in line with the centralities of the network. It was found that ‘freshwater’, ‘clean energy’, ‘runoff regulation’, ‘climate regulation’, ‘research and education’ and ‘infrastructure and engineering’ are the services that play critical roles in H-K, and they were then applied to assess the impact of cryosphere services on the national SDG priorities. We subsequently identified a set of principal indicators in relation to the key targets of national SDG priorities, which has the explanation up to 85% of six entry points (SEPs) to advance SDGs of each country in H-K. In conjunction with the centrality of the key targets to be contributed by the overall cryosphere services in the network for each country, the dependency of SEPs on the cryosphere services can be established through principal indicators in association with the national SDG priorities in H-K countries

Ultrasound-responsive microparticles from droplet microfluidics

Ultrasound (US)-responsive microparticles show broad potential in controlled drug delivery systems. Compare with the traditional micron-scale material fabrication methods, capillary microfluidic technology features superior advantages in large-scale production, batch-to-batch similarity, high encapsulation efficiency, low cost, and so on. The excellent maneuverability and customizability of the capillary microfluidic devices allow the production of microparticles with various functionalities and fine-tuned chemical compartments. Moreover, the flexible regulation of the particle size and core-shell ratio can be easily realized by modulating the capillary orifices and flow rates of microfluidic channels. In this review, we introduce the fabrication of US-responsive microparticles with specific core-shell structures via capillary microfluidic methods, from single emulsion to triple emulsions. Then, we address some particular examples, where the drug delivery and US-triggered cargo release capacity of these microfluidic microparticles are demonstrated. Finally, we conclude the advanced achievements of the US-responsive microfluidic microparticles, summarize the obstacles to the development of this interdisciplinary field, and prospect their future applications

Combining affinity selection and specific ion mobility for microchip protein sensing

The sensitive detection of proteins is a key objective in many areas of biomolecular science, ranging from biophysics to diagnostics. However, sensing in complex biological fluids is hindered by non-specific interactions with off-target species. Here, we describe and demonstrate an assay that utilises both the chemical and physical properties of the target species to achieve high selectivity, in a manner not possible by chemical complementarity alone, in complex media. We achieve this objective through a combinatorial strategy, by simultaneously exploiting free-flow electrophoresis for target selection, on the basis of electrophoretic mobility, and conventional affinity-based selection. In addition, we demonstrate amplification of the resultant signal by a catalytic DNA nano-circuit. This approach brings together the inherent solution-phase advantages of microfluidic sample handling with isothermal, enzyme-free signal amplification. With this method, no surface immobilisation or washing steps are required and our assay is well suited to mono-epitopic targets, presenting advantages over conventional ELISA techniques