An ultrawide field-of-view pinhole compound eye using hemispherical nanowire array for robot vision.

Garnering inspiration from biological compound eyes, artificial vision systems boasting a vivid range of diverse visual functional traits have come to the fore recently. However, most of these artificial systems rely on transformable electronics, which suffer from the complexity and constrained geometry of global deformation, as well as potential mismatches between optical and detector units. Here, we present a unique pinhole compound eye that combines a three-dimensionally printed honeycomb optical structure with a hemispherical, all-solid-state, high-density perovskite nanowire photodetector array. The lens-free pinhole structure can be designed and fabricated with an arbitrary layout to match the underlying image sensor. Optical simulations and imaging results matched well with each other and substantiated the key characteristics and capabilities of our system, which include an ultrawide field of view, accurate target positioning, and motion tracking function. We further demonstrate the potential of our unique compound eye for advanced robotic vision by successfully completing a moving target tracking mission.

A Review on the Carbonation of Steel Slag: Properties, Mechanism, and Application.

Steel slag is a by-product of the steel industry and usually contains a high amount of f-CaO and f-MgO, which will result in serious soundness problems once used as a binding material and/or aggregates. To relieve this negative effect, carbonation treatment was believed to be one of the available and reliable methods. By carbonation treatment of steel slag, the phases of f-CaO and f-MgO can be effectively transformed into CaCO3 and MgCO3, respectively. This will not only reduce the expansive risk of steel slag to improve the utilization of steel slag further but also capture and store CO2 due to the mineralization process to reduce carbon emissions. In this study, based on the physical and chemical properties of steel slag, the carbonation mechanism, factors affecting the carbonation process, and the application of carbonated steel slag were reviewed. Eventually, the research challenge was also discussed.

A facile and smart strategy to enhance bone regeneration with efficient vitamin D3 delivery through sterosome technology.

The spontaneous healing of critical-sized bone defects is often limited, posing an increased risk of complications and suboptimal outcomes. Osteogenesis, a complex process central to bone formation, relies significantly on the pivotal role of osteoblasts. Despite the well-established osteogenic properties of vitamin D3 (VD3), its lipophilic nature confines administration to oral or muscle injection routes. Therefore, a strategic therapeutic approach involves designing a multifunctional carrier to enhance efficacy, potentially incorporating it into the delivery system. Here, we introduce an innovative sterosome-based delivery system, utilizing palmitic acid (PA) and VD3, aimed at promoting osteogenic differentiation and facilitating post-defect bone regeneration. The delivery system exhibited robust physical characteristics, including excellent stability, loading efficiency, sustained drug release and high cellular uptake efficiency. Furthermore, comprehensive investigations demonstrated outstanding biocompatibility and osteogenic potential in both 2D and 3D in vitro settings. A critical-sized calvarial defect model in mice recapitulated the notable osteogenic effects of the sterosomes in vivo. Collectively, our research proposes a clinically applicable strategy for bone healing, leveraging PA/VD3 sterosomes as an efficient carrier to deliver VD3 and enhance bone regenerative effects.

Reduction-Active Antisolvent: A Universal and Innovative Strategy of Further Ameliorating Additive Optimization for High Efficiency Perovskite Solar Cells.

To further ameliorate current additive engineering of perovskites for viable applications, the inherent limitations should be overcome; these include weakened coordination of the dopants to the [PbI6]4- octahedra during crystallization and ubiquity of ineffective bonding sites. Herein, we introduce a facile strategy for synthesizing a reduction-active antisolvent. Washing with reduction-active PEDOT:PSS-blended antisolvent substantially enhances the intrinsic polarity of the Lewis acid (Pb2+) in [PbI6]4- octahedra, which causes significant strengthening of the coordinate bonding between additives and perovskite. Thus, coordination of the additive to the perovskite becomes much stable. Additionally, the enhanced coordination ability of Pb2+ can enhance the effective bonding sites and further enhance the efficacy of additive optimization to the perovskite. Here, we demonstrate five different additives as dopant bases and repeatedly verify the universality of this approach. The photovoltaic performance and stability of doped-MAPbI3 devices are further improved, revealing the advanced potential of additive engineering.

High sensitivity gas pressure sensor based on different inner diameter quartz capillary cascading and Vernier effect.

In this paper, a highly sensitive optical fiber gas pressure sensor is proposed and experimentally verified. The sensor is composed of two Fabry-Pérot (F-P) cavities, and two F-P cavities are fabricated by a single-mode fiber and two quartz capillaries with different inner diameters splicing. Among them, the small inner diameter capillary is used as a gas channel connecting the large inner diameter capillary and the external environment. The manufacturing process of the sensor only involves capillary cleaver and splicing and does not involve other complex manufacturing technologies. By correctly adjusting the length of the two quartz capillaries, when the free spectral range of the two F-P cavities is very close, the optical Vernier effect will be observed and used as a sensitive probe for detecting gas pressure. The experimental results show that, in the pressure range of 0-0.8 MPa, the gas pressure sensitivity of the sensor reaches -81.73 nm/MPa with a linearity of 99.7%, and the temperature cross-sensitivity is only 1.82 kPa/°C. Due to its easy manufacture, high sensitivity, compact structure, and small volume, the sensor has become one of the preferred structures for large-scale use in the field of gas sensing.

Temperature-Modulated Selective Detection of Part-per-Trillion NO2 Using Platinum Nanocluster Sensitized 3D Metal Oxide Nanotube Arrays.

Semiconductor chemiresistive gas sensors play critical roles in a smart and sustainable city where a safe and healthy environment is the foundation. However, the poor limits of detection and selectivity are the two bottleneck issues limiting their broad applications. Herein, a unique sensor design with a 3D tin oxide (SnO2 ) nanotube array as the sensing layer and platinum (Pt) nanocluster decoration as the catalytic layer, is demonstrated. The Pt/SnO2 sensor significantly enhances the sensitivity and selectivity of NO2 detection by strengthening the adsorption energy and lowering the activation energy toward NO2 . It not only leads to ultrahigh sensitivity to NO2 with a record limit of detection of 107 parts per trillion, but also enables selective NO2 sensing while suppressing the responses to interfering gases. Furthermore, a wireless sensor system integrated with sensors, a microcontroller, and a Bluetooth unit is developed for the practical indoor and on-road NO2 detection applications. The rational design of the sensors and their successful demonstration pave the way for future real-time gas monitoring in smart home and smart city applications.

Development of a duplex real-time reverse transcription-polymerase chain reaction assay for the simultaneous detection of goose astrovirus genotypes 1 and 2.

Goose astrovirus (GAstV) is a highly infectious pathogen that causes gout in goslings (<15 old) with typical symptoms of white urate disposition on the surface of the visceral organs and articular cavity, and a high mortality rate up to 50 %. To establish a real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay for the rapid detection of the two GastV genotypes(GAstV-1 and GAstV-2), two pairs of primers and a pair of matching TaqMan probes were designed based on conserved regions of the ORF1b gene. The established duplex rRT-PCR assay showed no cross-reactivity with 10 other common waterfowl pathogens. The minimum detection limit was 10 copies/reaction for both GAstV-1 and GAstV-2. To validate the assay, 36 cloacal swabs from experimentally infected goslings and 33 field clinical samples were tested. The assay results of the experimentally infected goslings matched the infection scheme. The positive rates of GAstV-1 and GAstV-2 in the field clinical samples were 36.36 % and 54.55 %, respectively, and the co-infection rate of the two viruses was 21.21 % based on the duplex rRT-PCR assay. In conclusion, the established assay represents a specific, sensitive, and convenient tool for detecting GAstV-1, GAstV-2, and their co-infections, and for conducting epidemiological surveys.

Microheater Integrated Nanotube Array Gas Sensor for Parts-Per-Trillion Level Gas Detection and Single Sensor-Based Gas Discrimination.

Real-time monitoring of health threatening gases for chemical safety and human health protection requires detection and discrimination of trace gases with proper gas sensors. In many applications, costly, bulky, and power-hungry devices, normally employing optical gas sensors and electrochemical gas sensors, are used for this purpose. Using a single miniature low-power semiconductor gas sensor to achieve this goal is hardly possible, mostly due to its selectivity issue. Herein, we report a dual-mode microheater integrated nanotube array gas sensor (MINA sensor). The MINA sensor can detect hydrogen, acetone, toluene, and formaldehyde with the lowest measured limits of detection (LODs) as 40 parts-per-trillion (ppt) and the theoretical LODs of ∼7 ppt, under the continuous heating (CH) mode, owing to the nanotubular architecture with large sensing area and excellent surface catalytic activity. Intriguingly, unlike the conventional electronic noses that use arrays of gas sensors for gas discrimination, we discovered that when driven by the pulse heating (PH) mode, a single MINA sensor possesses discrimination capability of multiple gases through a transient feature extraction method. These above features of our MINA sensors make them highly attractive for distributed low-power sensor networks and battery-powered mobile sensing systems for chemical/environmental safety and healthcare applications.

Wireless Self-Powered High-Performance Integrated Nanostructured-Gas-Sensor Network for Future Smart Homes.

The accelerated evolution of communication platforms including Internet of Things (IoT) and the fifth generation (5G) wireless communication network makes it possible to build intelligent gas sensor networks for real-time monitoring chemical safety and personal health. However, this application scenario requires a challenging combination of characteristics of gas sensors including small formfactor, low cost, ultralow power consumption, superior sensitivity, and high intelligence. Herein, self-powered integrated nanostructured-gas-sensor (SINGOR) systems and a wirelessly connected SINGOR network are demonstrated here. The room-temperature operated SINGOR system can be self-driven by indoor light with a Si solar cell, and it features ultrahigh sensitivity to H2, formaldehyde, toluene, and acetone with the record low limits of detection (LOD) of 10, 2, 1, and 1 ppb, respectively. Each SINGOR consisting of an array of nanostructured sensors has the capability of gas pattern recognition and classification. Furthermore, multiple SINGOR systems are wirelessly connected as a sensor network, which has successfully demonstrated flammable gas leakage detection and alarm function. They can also achieve gas leakage localization with satisfactory precision when deployed in one single room. These successes promote the development of using nanostructured-gas-sensor network for wide range applications including smart home/building and future smart city.

Restoration Effect and Tribological Behavior of Hyaluronic Acid Reinforced with Graphene Oxide in Osteoarthritis.

Osteoarthritis (OA) is an unavoidable degenerative disease of the human body. A relatively efficient and desirable treatment exists that leads to the ecological restoration of cartilage through the adjustments of the micro-environment of the human body and relies on its self-repairing ability. In the present study, lubricants were injected into the knee joints of rats. Hyaluronic acid (HA) reinforced with graphene oxide (GO) provided a lubricating condition for cartilage repair, as well as played an important role in the regulation of the microenvironment in the joint cavity. The experimental results demonstrated that the stability of HA lubricant reinforced with GO was dependent on the presence of oxygen-containing functional groups on the graphite oxide nano-sheets. The GO could be evenly distributed on the joint surface in the form of a solid lubrication film and was able to decrease the articular cartilage necrosis and the ratio of MMP-3/TIMP-1 through TIMP-1 activity increase. The HA lubricant reinforced with GO demonstrated an apparent antifriction effect on the joint surface, providing a stable environment for cartilage repair. It was also conducive to long-term lubrication improvement. The adjustment of micro-environment between the cartilage friction interfaces might contribute to the treatment of osteoarthritis through ecological restoration.