Oxidation Flow Reactor Results in a Chinese Megacity Emphasize the Important Contribution of S/IVOCs to Ambient SOA Formation.

Oxygenated volatile organic compounds (OVOCs) and secondary organic aerosol (SOA) formation potential of ambient air in Guangzhou, China was investigated using a field-deployed oxidation flow reactor (OFR). The OFR was used to mimic hours to weeks of atmospheric exposure to hydroxyl (OH) radicals within the 2-3 min residence time. A comprehensive investigation on the variation of VOCs and OVOCs as a function of OH exposure is shown. Substantial formation of organic acids and nitrogen-containing OVOC species were observed. Maximum SOA formation in the OFR was observed following 1-4 equiv days' OH exposure. SOA produced from known/measured VOC/IVOC precursors such as single-ring aromatics and long-chain alkanes can account for 52-75% of measured SOA under low NOx and 26-60% under high NOx conditions based on laboratory SOA yield parametrizations. To our knowledge, this is the first time that the contribution (8-20%) of long-chain (C8-C20) alkane oxidation to OFR SOA formation was quantified from direct measurement. By additionally estimating contribution from unmeasured semivolatile and intermediate volatility compounds (S/IVOCs) that are committed with C8-C20 alkanes, 64-100% of the SOA formation observed in the OFR can be explained, signifying the important contribution of S/IVOCs such as large cyclic alkanes to ambient SOA.

In-tube micro-pyramidal silicon nanopore for inertial-kinetic sensing of single molecules.

Electrokinetic force has been the major choice for driving the translocation of molecules through a nanopore. However, the use of this approach is limited by an uncontrollable translocation speed, resulting in non-uniform conductance signals with low conformational sensitivity, which hinders the accurate discrimination of the molecules. Here, we show the use of inertial-kinetic translocation induced by spinning an in-tube micro-pyramidal silicon nanopore fabricated using photovoltaic electrochemical etch-stop technique for biomolecular sensing. By adjusting the kinetic properties of a funnel-shaped centrifugal force field while maintaining a counter-balanced state of electrophoretic and electroosmotic effect in the nanopore, we achieved regulated translocation of proteins and obtained stable signals of long and adjustable dwell times and high conformational sensitivity. Moreover, we demonstrated instantaneous sensing and discrimination of molecular conformations and longitudinal monitoring of molecular reactions and conformation changes by wirelessly measuring characteristic features in current blockade readouts using the in-tube nanopore device.

Angular-Inertia Regulated Stable and Nanoscale Sensing of Single Molecules Using Nanopore-In-A-Tube.

Nanopore is commonly used for high-resolution, label-free sensing, and analysis of single molecules. However, controlling the speed and trajectory of molecular translocation in nanopores remains challenging, hampering sensing accuracy. Here, the study proposes a nanopore-in-a-tube (NIAT) device that enables decoupling of the current signal detection from molecular translocation and provides precise angular inertia-kinetic translocation of single molecules through a nanopore, thus ensuring stable signal readout with high signal-to-noise ratio (SNR). Specifically, the funnel-shaped silicon nanopore, fabricated at a 10-nm resolution, is placed into a centrifugal tube. A light-induced photovoltaic effect is utilized to achieve a counter-balanced state of electrokinetic effects in the nanopore. By controlling the inertial angle and centrifugation speed, the angular inertial force is harnessed effectively for regulating the translocation process with high precision. Consequently, the speed and trajectory of the molecules are able to be adjusted in and around the nanopore, enabling controllable and high SNR current signals. Numerical simulation reveals the decisive role of inertial angle in achieving uniform translocation trajectories and enhancing analyte-nanopore interactions. The performance of the device is validated by discriminating rigid Au nanoparticles with a 1.6-nm size difference and differentiating a 1.3-nm size difference and subtle stiffness variations in flexible polyethylene glycol molecules.

Transformable Soft Gripper: Uniting Grasping and Suction for Amphibious Cross-Scale Objects Grasping.

Robotic grasping plays a pivotal role in real-world interactions for robots. Existing grippers often limit functionality to a single grasping mode-picking or suction. While picking handles smaller objects and suction adapts to larger ones, integrating these modes breaks scale boundaries, expanding the robot's potential in real applications. This article introduces grasping modes transformable soft gripper capable of achieving amphibious cross-scale objects grasping. Despite its compact and fully scalable design (20 mm in diameter prototype), it morphs into two configurations, gripping objects from 10% (2 mm) to over 1000% (200 mm) of its size, spanning a vast 100-fold range. To enhance its grasping efficacy, we derived theoretical analytical models for the two distinct grasping modes. Subsequently, we present a detailed illustration of the gripper's fabrication process. Experimental validation demonstrates the gripper's success in attaching or detaching everyday items and industrial products, achieving high success rates in both air and underwater scenarios. Amphibious grasping and card manipulation demonstrations underscore the practicality of this transformative soft robotics approach.

Comparative responses of cell growth and related extracellular polymeric substances in Tetraselmis sp. to nonylphenol, bisphenol A and 17α-ethinylestradiol.

Estuarine ecosystems near mega-cities are sinks of anthropogenic endocrine disrupting chemicals (EDCs). As the most important primary producer, indigenous microalgae and their secreted extracellular polymeric substances (EPSs) might interact with EDCs and contribute to their fate and risk. Tetraselmis sp. is a representative model of estuarine microalga, for which EDC toxicity and its effects on EPS synthesis have rarely been studied. Through microalgal isolation, algal cell growth tests, EDC removal and the characterization of related EPS profiles, the present work intends to clarify the comparative responses of Tetraselmis sp. to nonylphenol (NP), bisphenol A (BPA) and 17α-ethinylestradiol (EE2). The results showed that the half inhibitory concentration on cell growth was 0.190-0.313 mg/dm3 for NP, which was one order of magnitude lower than the comparable values for BPA and EE2 at 2.072-3.254 mg/dm3. Regarding chlorophyll, NP induced its degradation, EE2 led to its decreased production, and BPA had no obvious effect. Under EDC stress, only the concentrations of colloidal polysaccharides and proteins responded dose-dependently to EE2. Except for the colloidal fraction in the EE2 treatment group, the increase in neutral monosaccharides, especially glucose and galactose, was a common response to EDCs. Compared to the recalcitrant BPA, NP underwent abiotic degradation in alga-free water, and EE2 could be biodegraded in water containing this microalga. The chemical-specific responses of cell growth, chlorophyll and related EPS profiles were driven by the different fates of EDCs, and the underlying mechanism was further discussed. The results obtained in the present work are of critical importance for understanding the fate and effects of different EDCs mediated by microalgae and their related EPSs.