During the past decade, biofuel cells (BFCs) have emerged as an emerging technology on account of their ability to directly generate electricity from biologically renewable catalysts and fuels. Due ...to the boost in nanotechnology, significant advances have been accomplished in BFCs. Although it is still challenging to promote the performance of BFCs, adopting nanostructured materials for BFC construction has been extensively proposed as an effective and promising strategy to achieve high energy production. In this review, we presented the major novel nanostructured materials applied for BFCs and highlighted the breakthroughs in this field. Based on different natures of the bio-catalysts and electron transfer process at the bio-electrode surfaces, the fundamentals of BFC systems, including enzymatic biofuel cells (EBFCs) and microbial fuel cells (MFCs), have been elucidated. In particular, the principle of electrode materials design has been detailed in terms of enhancing electrical communications between biological catalysts and electrodes. Furthermore, we have provided the applications of BFCs and potential challenges of this technology.
The review provides comprehensive discussions about electrode materials of BFCs and prospects of this technology for real-word applications.
Quantifying the binding kinetics and affinities of protein–small molecule interactions is critical for biomarker validation, drug discovery, and deep understanding of various biological processes at ...the molecular‐scale. Novel approaches are demanded as most common label‐free techniques are mass‐sensitive, which are not suitable for the detection of small molecule interactions. Here, an optical imaging platform is developed to measure the binding kinetics of both protein–small molecules and protein–ions based on monolayer MoS2, an ultra‐thin 2D material whose optical absorption is extremely sensitive to charge. A model is established to calibrate the optical response due to the charged analyte binding and it is applied to quantify the interactions between abl1 kinase and different small‐molecule inhibitors. Such a presented method is capable of distinguishing different inhibitors binding to a wild or mutated kinase, which provides guidance for drug evaluation and drug mechanism exploration. The binding kinetics of calcium ions to calmodulin is also measured, further broadening the application field of the method. In addition, the imaging capability allows mapping the local binding kinetics of the molecular interactions with a high resolution, which reveals visible spatial variability and offers a promising tool for studying heterogeneous local interfacial interactions.
Here, a charge‐sensitive detection strategy for the study of protein–small molecule interactions with a monolayer MoS2‐based optical imaging platform is described, which shows high sensitivity, good specificity, and a relatively low detection limit. The method is demonstrated as a promising tool for studying the local interfacial interaction and provides guidance for drug mechanism exploration and pharmacodynamic analysis.
pH-responsive drug-delivery systems Zhu, Ying-Jie; Chen, Feng
Chemistry, an Asian journal,
February 2015, Volume:
10, Issue:
2
Journal Article
Peer reviewed
In many biomedical applications, drugs need to be delivered in response to the pH value in the body. In fact, it is desirable if the drugs can be administered in a controlled manner that precisely ...matches physiological needs at targeted sites and at predetermined release rates for predefined periods of time. Different organs, tissues, and cellular compartments have different pH values, which makes the pH value a suitable stimulus for controlled drug release. pH-Responsive drug-delivery systems have attracted more and more interest as "smart" drug-delivery systems for overcoming the shortcomings of conventional drug formulations because they are able to deliver drugs in a controlled manner at a specific site and time, which results in high therapeutic efficacy. This focus review is not intended to offer a comprehensive review on the research devoted to pH-responsive drug-delivery systems; instead, it presents some recent progress obtained for pH-responsive drug-delivery systems and future perspectives. There are a large number of publications available on this topic, but only a selection of examples will be discussed.
The rapid increase in both the quantity and complexity of data that are being generated daily in the field of environmental science and engineering (ESE) demands accompanied advancement in data ...analytics. Advanced data analysis approaches, such as machine learning (ML), have become indispensable tools for revealing hidden patterns or deducing correlations for which conventional analytical methods face limitations or challenges. However, ML concepts and practices have not been widely utilized by researchers in ESE. This feature explores the potential of ML to revolutionize data analysis and modeling in the ESE field, and covers the essential knowledge needed for such applications. First, we use five examples to illustrate how ML addresses complex ESE problems. We then summarize four major types of applications of ML in ESE: making predictions; extracting feature importance; detecting anomalies; and discovering new materials or chemicals. Next, we introduce the essential knowledge required and current shortcomings in ML applications in ESE, with a focus on three important but often overlooked components when applying ML: correct model development, proper model interpretation, and sound applicability analysis. Finally, we discuss challenges and future opportunities in the application of ML tools in ESE to highlight the potential of ML in this field.
DNA nanotechnology engineered at the solid-liquid interface has advanced our fundamental understanding of DNA hybridization kinetics and facilitated the design of improved biosensing, bioimaging and ...therapeutic platforms. Three research branches of DNA nanotechnology exist: (i) structural DNA nanotechnology for the construction of various nanoscale patterns; (ii) dynamic DNA nanotechnology for the operation of nanodevices; and (iii) functional DNA nanotechnology for the exploration of new DNA functions. Although the initial stages of DNA nanotechnology research began in aqueous solution, current research efforts have shifted to solid-liquid interfaces. Based on shape and component features, these interfaces can be classified as flat interfaces, nanoparticle interfaces, and soft interfaces of DNA origami and cell membranes. This review briefly discusses the development of DNA nanotechnology. We then highlight the important roles of structural DNA nanotechnology in tailoring the properties of flat interfaces and modifications of nanoparticle interfaces, and extensively review their successful bioapplications. In addition, engineering advances in DNA nanodevices at interfaces for improved biosensing both
in vitro
and
in vivo
are presented. The use of DNA nanotechnology as a tool to engineer cell membranes to reveal protein levels and cell behavior is also discussed. Finally, we present challenges and an outlook for this emerging field.
This review provides an insight into the bioapplications of DNA nanotechnology at the solid-liquid interfaces, including flat interfaces, nanoparticle interfaces and soft interfaces.
The hurricane post‐landfall wind speed decay is closely linked to the inland damage potential. We introduce the wind decay period as a new metric for assessing the time required for a landfalling ...hurricane to dissipate to the intensity below tropical storm strength. In the continental United States, the wind decay period was generally decreasing during 1900–1979 but significantly increased during 1980–2019. The 120‐year trend pattern of the wind decay period has been found to be correlated with the Atlantic Multidecadal Oscillation. Meanwhile, we show that the storm's distance of movement is not changing simultaneously with the decay period due to the variance of storm translation speed. The spatial variation of the wind decay is also confirmed. While the majority of the historical Gulf landfall hurricanes decayed below tropical storm strength, landfalling hurricanes over Florida in particular, tend to cross the peninsula retaining wind speeds greater than 34‐kt.
Plain Language Summary
The destructive forces from a hurricane can penetrate far inland. The wind speed decay after hurricanes making landfall is critical for estimating potential inland damages. We introduce the wind decay period as a measurement of the time required for a landfalling hurricane to decay below tropical storm strength. The wind decay period helps quantify the longevity of the storm moving inland at a certain intensity. With the focus on the period 1900–2019, hurricanes making landfall over the continental United States show a decrease of longevity before 1980 but significantly increase thereafter. This trend shows a relationship to the Atlantic Multidecadal Oscillation. Meanwhile, the distance of the storm moving over land is not increasing with longevity, indicating the variance of the storm's speed of movement also plays an important role. Spatial variations exist where landfalling hurricanes over the Atlantic East coast and Florida peninsula are likely to turn back to the ocean without decaying to below the tropical storm strength.
Key Points
The wind decay period and decay distance are introduced to quantify the longevity of an inland moving tropical cyclone at a certain intensity level
Prior to 1980, hurricanes making landfall over the continental United States show a downward trend of the wind decay period but rebounds significantly after 1980
A possible correlation between the hurricane wind decay period and the Atlantic Multidecadal Oscillation is found
Many applications proposed for functional nanofibers require their assembly into a monolithic cellular structure. The ability to maintain structural integrity upon large deformation is essential to ...ensure a macroscopic cellular material that functions reliably. However, it remains a great challenge to achieve high elasticity in three-dimensional (3D) nanofibrous networks. Here, we report a strategy to create fibrous, isotropically bonded elastic reconstructed (FIBER) aerogels with a hierarchical cellular structure and superelasticity by combining electrospun nanofibers and the freeze-shaping technique. Our approach allows the intrinsically lamellar deposited electrospun nanofibers to assemble into elastic bulk aerogels with tunable porous structure and wettability on a large scale. The resulting FIBER aerogels exhibit the integrated properties of ultralow density (<30 mg cm–3), rapid recovery from 80% compression strain, superhydrophobic-superoleophilic wettability, and high pore tortuosity. More interestingly, the FIBER aerogels can effectively separate surfactant-stabilized water-in-oil emulsions, solely using gravity, with high flux (maximum of 8140 ± 220 L m–2 h–1) and high separation efficiency, which match well with the requirements for treating the real emulsions. The synthesis of FIBER aerogels also provides a versatile platform for exploring the applications of nanofibers in a self-supporting, structurally adaptive, and 3D macroscopic form.
The quest for new techniques to measure single nanomaterials is a great impetus to research efforts to understand individual behaviours. Here, we develop an electrochemiluminescence (ECL) microscopy ...for visualization of stochastic collision electrochemistry of single nano-emitters without the interference of current and optical background. This design uses a water-immersion objective to capture the ECL emission of nanoparticles near the specular electrode surface for enhancing light collection efficiency. The approach enables us to trace the collision trajectory of multiple nanoparticles and spatially distinguish simultaneous collisions. Results reveal that collision types, frequencies and ECL intensities significantly depend on surface natures, particle concentrations, and diffusion fluxes. By recording successive collisions, we develop a "relay probe" sensing platform for long-term research. This imaging technique displays great potential for applications in single-particle electrochemical and analytical research.
To make organic solar cells (OSCs) more competitive in the diverse photovoltaic cell technologies, it is very important to demonstrate that OSCs can achieve very good efficiencies and that their cost ...can be reduced. Here, a pair of nonfullerene small‐molecule acceptors, IT‐2Cl and IT‐4Cl, is designed and synthesized by introducing easy‐synthesis chlorine substituents onto the indacenodithieno3,2‐bthiophene units. The unique feature of the large dipole moment of the CCl bond enhances the intermolecular charge‐transfer effect between the donor–acceptor structures, and thus expands the absorption and down shifts the molecular energy levels. Meanwhile, the introduction of CCl also causes more pronounced molecular stacking, which also helps to expand the absorption spectrum. Both of the designed OSCs devices based on two acceptors can deliver a power conversion efficiency (PCE) greater than 13% when blended with a polymer donor with a low‐lying highest occupied molecular orbital level. In addition, since IT‐2Cl and IT‐4Cl have very good compatibility, a ternary OSC device integrating these two acceptors is also fabricated and obtains a PCE greater than 14%. Chlorination demonstrates effective ability in enhancing the device performance and facile synthesis route, which both deserve further exploitation in the modification of photovoltaic materials.
A pair of nonfullerene small‐molecule acceptors, IT‐2Cl and IT‐4Cl, is designed and synthesized by easy‐synthesis chlorine substituents. The CCl bond enhances the intermolecular charge‐transfer effect between the donor–acceptor structures and molecular structure order. Both binary devices show efficiency beyond 13%, and a ternary organic solar cell device integrating these two acceptors obtains an efficiency greater than 14%.
Previous researches on high-energy photon events from gamma-ray bursts (GRBs) suggest a light speed variation v(E)=c(1−E/ELV) with ELV=3.6×1017 GeV, together with a pre-burst scenario that ...hight-energy photons come out about 10 seconds earlier than low-energy photons at the GRB source. However, in the Lorentz invariance violating scenario with an energy dependent light speed considered here, high-energy photons travel slower than low-energy photons due to the light speed variation, so that they are usually detected after low-energy photons in observed GRB data. Here we find four high-energy photon events which were observed earlier than low-energy photons from Fermi Gamma-ray Space Telescope (FGST), and analysis on these photon events supports the pre-burst scenario of high energy photons from GRBs and the energy dependence of light speed listed above.
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