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In recent years, yttrium oxide coatings prepared by atmospheric plasma spraying (APS) have been employed extensively in semiconductor processing equipment. Meanwhile, defects in yttrium oxide coating, such as unmelted particles and pores, reduce the etching resistance of the coating. In this work, two yttrium oxide coatings were prepared by in situ laser-assisted plasma spraying (LAPS) coupled with a 500 W and 600 W laser for comparison with a coating prepared by APS, and the effects of the laser on the coating properties were investigated. The results show that the surface roughness was reduced by 25.7% (500 W) and 25.3% (600 W) and the porosity was reduced by 52.3% (500 W) and 36.9% (600 W) after laser coupling. After being etched by CF4/CHF3 for a long time, it was observed from SEM, EDS and XPS analyses that the intensity ratios of the Y-F bonds in the coating were 1 (APS):1.3 (LAPS+500W):1.1 (LAPS+600W), which indicated that the LAPS+500W coating had a thicker fluorination layer. It was also observed that the fluorination layer at the defect was first eroded; then, the erosion area gradually spread to the surrounding area, and finally, the fluorination layer was etched. This indicated that the defects had a significant impact on the etching resistance. Consequently, the LAPS+500W coating with fewer defects and a thicker fluorination layer showed the lowest etching rate. Therefore, in situ laser-assisted plasma spraying coupled with an appropriate laser power is an effective method to improve the performance of yttrium oxide coatings. [ABSTRACT FROM AUTHOR]

A light-addressable potentiometric sensor (LAPS) is a semiconductor-based sensor platform for sensing and imaging of various chemical species. Being a potentiometric sensor, no faradaic current flows through its sensing surface, and no electrochemical reaction takes place in the course of LAPS measurement. In this study, a four-electrode system is proposed, in which a LAPS is combined with the conventional three-electrode electrochemical system. A LAPS is included as the fourth electrode for potentiometric sensing and imaging of the target analyte in the course of an electrochemical reaction taking place on the surface of the working electrode. The integrated system will be useful for analyzing dynamic processes, where both the electrochemical process on the electrode surface and the ion distribution in the solution need to be simultaneously investigated. Different grounding modes of control circuits that can simultaneously conduct potentiostatic/galvanostatic polarization and LAPS measurement are designed, and their functionalities are tested. The interference between polarization and LAPS measurement will also be discussed. [ABSTRACT FROM AUTHOR]

A light-addressable potentiometric sensor (LAPS) is a chemical sensor that is based on the field effect in an electrolyte–insulator–semiconductor structure. It requires modulated illumination for generating an AC photocurrent signal that responds to the activity of target ions on the sensor surface. Although high-power illumination generates a large signal, which is advantageous in terms of the signal-to-noise ratio, excess light power can also be harmful to the sample and the measurement. In this study, we tested different waveforms of modulated illuminations to find an efficient illumination for a LAPS that can enlarge the signal as much as possible for the same input light power. The results showed that a square wave with a low duty ratio was more efficient than a sine wave by a factor of about two. [ABSTRACT FROM AUTHOR]

Macronutrients (carbohydrates, fat and protein) are the cornerstones of daily diet, among which carbohydrates provide energy for the muscles and central nervous system during movement and exercise. The breakdown of carbohydrates starts in the oral cavity, where they are primarily hydrolyzed to glucose and then metabolized to organic acids. The end products may have an impact on the oral microenvironment, so it is necessary to monitor the process of microbial metabolism and to measure the pH change. Although a pH meter has been widely used, it is limited by its sensitivity. We then introduce a light addressable potentiometric sensor (LAPS), which has been used in extracellular acidification detection of living cells with the advantages of being objective, quantitative and highly sensitive. However, it is difficult to use in monitoring bacterial metabolism because bacteria cannot be immobilization on the LAPS chip as easily as living cells. Therefore, a microphysiometric system integrated with Transwell insert and microfluidic LAPS chip was designed and constructed to solve this problem. The decrease in pH caused by glucose fermentation in Lactobacillus rhamnosus was successfully measured by this device. This proves the feasibility of the system for metabolism detection of non-adhere targets such as microorganisms and even 3D cells and organoids. [ABSTRACT FROM AUTHOR]

The light-addressable potential sensor (LAPS) was invented in 1988 and has developed into a multi-functional platform for chemical and biological sensing in recent decades. Its surface can be flexibly divided into multiple regions or pixels through light addressability, and each of them can be sensed independently. By changing sensing materials and optical systems, the LAPS can measure different ions or molecules, and has been applied to the sensing of various chemical and biological molecules and cells. In this review, we firstly describe the basic principle of LAPS and the general configuration of a LAPS measurement system. Then, we outline the most recent applications of LAPS in chemical sensing, biosensing and cell monitoring. Finally, we enumerate and analyze the development trends of LAPS from the aspects of material and optical improvement, hoping to provide a research and application perspective for chemical sensing, biosensing and imaging technology. [ABSTRACT FROM AUTHOR]

Cadaveric decellularized bone tissue is utilized as an allograft in many musculoskeletal surgical procedures. Typically, the allograft acts as a scaffold to guide tissue regeneration with superior biocompatibility relative to synthetic scaffolds. Traditionally these scaffolds are machined into the required dimensions and shapes. However, the geometrical simplicity and, in some cases, limited dimensions of the donated tissue restrict the use of allograft scaffolds. This could be overcome by additive manufacturing using granulated bone that is both decellularized and demineralized. In this study, the large area projection sintering (LAPS) method is evaluated as a fabrication method to build porous structures composed of granulated cortical bone bound by polycaprolactone (PCL). This additive manufacturing method utilizes visible light to selectively cure the deposited material layer-by-layer to create 3D geometry. First, the spreading behavior of the composite mixtures is evaluated and the conditions to attain improved powder bed density to fabricate the test specimens are determined. The tensile strength of the LAPS fabricated samples in both dry and hydrated states are determined and compared to the demineralized cancellous bone allograft and the heat treated demineralized-bone/PCL mixture in mold. The results indicated that the projection sintered composites of 45-55 wt %. Demineralized bone matrix (DBM) particulates produced strength comparable to processed and demineralized cancellous bone. [ABSTRACT FROM AUTHOR]

In a previous study, a thin In-Ga-Zn-oxide light addressable potentiometric sensor (IGZO LAPS) was indicated to have the advantages of low interference from ambient light, a high photocurrent and transfer efficiency, and a low cost. However, illumination optimization to obtain two-dimensional (2D) chemical images with better spatial resolutions has not been fully investigated. The trigger current and AC-modulated frequency of a 405-nm laser used to illuminate the fabricated IGZO LAPS were modified to check the photocurrent of the sensing area and SU8–2005 masking area, obtaining spatial resolution-related functions for the first time. The trigger current of illumination was adjusted from 0.020 to 0.030 A to compromise between an acceptable photocurrent and the integrity of the SU8–2005 masking layer. The photocurrent (PC) and differential photocurrent (DPC) versus scanning length (SL) controlled by an X-Y stage were used to check the resolved critical dimensions (CDs). The difference between resolved CD and optically measured CD (e.g., delta CD) measured at an AC frequency of 500 Hz revealed overall smaller values, supporting precise measurement in 2D imaging. The signal-to-noise ratio (SNR) has an optimized range of 2.0 to 2.15 for a better resolution for step spacings of both 10 and 2 μm in the scanning procedure to construct static 2D images. Under illumination conditions with a trigger current of 0.025 A and at an AC frequency of 500 Hz, the spatial resolution can be reduced to 10 μm from the pattern width of 6 μm. This developed methodology provides a quantitative evaluation with further optimization in spatial resolution without an extra cost for applications requiring a high spatial resolution, such as single-cell activity. [ABSTRACT FROM AUTHOR]

Simple Summary: The Cat/Dog–Owner Relationship Scale (C/DORS) is a questionnaire aimed to assess specific aspects of the pet–owner relationship. While the entire scale can be administered to both dog and cat owners, its validity and reliability have never been tested on dogs. Furthermore, validity and reliability of a scale may change depending on the respondents' language and cultural background. Since the C/DORS was developed in English, we aimed to translate it into Italian and assess its validity and reliability on a sample of Italian dog owners. The response scale was modified to improve the variability of the owners' responses. Overall, validity and reliability were good. The scale had the same three-factor structure (Perceived Emotional Closeness = PEC, Pet–Owner Interactions = POI, Perceived Costs = PC) reported for the original English version, although some items were removed because they did not fit the statistical model. The PEC subscale had the highest correlations with the subscales of the Lexington Attachment to Pets Scale. Finally, being a student owner was associated with higher PEC and POI scores. Conversely, owning a dog with behavioural problems was associated with lower PEC and higher PC. Owners whose dogs lived outdoors reported lower POI. Pet dog owners reported higher PEC than AAI dog owners. The Cat/Dog–Owner Relationship Scale (C/DORS) can be administered to both dog and cat owners. However, the scale as a whole has never been validated on a sample of dog owners. Furthermore, it has never been translated into Italian. The aim of this study was to translate the C/DORS into Italian, modify its response scale in order to improve the degree of response variability, and test its validity and reliability on a sample of dog-owners. Exploratory factor analysis revealed the same three-factor structure (Perceived Emotional Closeness = PEC, Pet–Owner Interactions = POI, Perceived Costs = PC) as the original English version, although some items had to be removed because of low- or cross-loadings. The validity of the construct was confirmed by confirmatory factor analysis, by the correlations between each of the subscales and the C/DORS total score, and by the correlations with the Lexington Attachment to Pets Scale. Cronbach's α values for each subscale were above acceptable levels. Student owners scored higher on PEC and POI than owners with other occupations. Owners of dogs with behavioural problems scored lower on PEC and higher on PC. Keeping the dog outdoor was associated with lower POI. Finally, pet dog owners scored higher on PEC than AAI dog owners. [ABSTRACT FROM AUTHOR]

About 75% energy demand and emissions all concentrate in urban areas, especially in the metropolises, placing a heavy burden on both the energy supply system and the environment system. To explore low emission pathways and provide policy recommendations for the Shanghai energy system and the environmental system to reach the carbon dioxide (CO2) peak by 2030 and attain emission reduction targets for local air pollutants (LAPs), a regional energy–environment optimization model was developed in this study, considering system costs, socio-economic development and technology. To verify the reliability of the model simulation and evaluate the model risk, a historical scenario was defined to calculate the emissions for 2004–2014, and the data were compared with the bottom-up emission inventory results. By considering four scenarios, we simulated the energy consumption and emissions in the period of 2020–2030 from the perspective of energy policies, economic measures and technology updates. We found that CO2 emissions might exceed the amount of 250 million tons by the end of 2020 under the current policy, and carbon tax with a price of 40 CNY per ton of carbon dioxide is an imperative measure to lower carbon emissions. Under the constraints, the emissions amount of SO2, NOx, PM10, and PM2.5 will be reduced by 95.3–180.8, 207.8–357.1, 149.4–274.5, and 59.5–119.8 Kt in 2030, respectively. [ABSTRACT FROM AUTHOR]

Severe hydrometeorological hazards such as floods, droughts, and thunderstorms are expected to increase in the future due to climate change. Due to the significant impacts of these phenomena, it is essential to develop new and advanced early warning systems for advance preparation of the population and local authorities (civil protection, government agencies, etc.). Therefore, reliable forecasts of extreme events, with high spatial and temporal resolution and a very short time horizon are needed, due to the very fast development and localized nature of these events. In very short time-periods (up to 6 h), small-scale phenomena can be described accurately by adopting a "nowcasting" approach, providing reliable short-term forecasts and warnings. To this end, a novel nowcasting system was developed and presented in this study, combining a data assimilation system (LAPS), a large amount of observed data, including XPOL radar precipitation measurements, the Chemical Hydrological Atmospheric Ocean wave System (CHAOS), and the WRF-Hydro model. The system was evaluated on the catastrophic flash flood event that occurred in the sub-urban area of Mandra in Western Attica, Greece, on 15 November 2017. The event was one of the most catastrophic flash floods with human fatalities (24 people died) and extensive infrastructure damage. The update of the simulations with assimilated radar data improved the initial precipitation description and led to an improved simulation of the evolution of the phenomenon. Statistical evaluation and comparison with flood data from the FloodHub showed that the nowcasting system could have provided reliable early warning of the flood event 1, 2, and even to 3 h in advance, giving vital time to the local authorities to mobilize and even prevent fatalities and injuries to the local population. [ABSTRACT FROM AUTHOR]

Crevice corrosion is a type of local corrosion which occurs when a metal surface is confined in a narrow gap on the order of 10 μm filled with a solution. Because of the inaccessible geometry, experimental methods to analyze the inner space of the crevice have been limited. In this study, a light-addressable potentiometric sensor (LAPS) was employed to estimate the potential distribution inside the crevice owing to the IR drop by the anodic current flowing out of the structure. Before crevice corrosion, the I–V curve of the LAPS showed a potential shift, depending on the distance from the perimeter. The shift reflected the potential distribution due to the IR drop by the anodic current flowing out of the crevice. After crevice corrosion, the corrosion current increased exponentially, and a local pH change was detected where the corrosion was initiated. A simple model of the IR drop was used to calculate the crevice gap, which was 12 μm—a value close to the previously reported values. Thus, the simultaneous measurement of the I–V curves obtained using a LAPS during potentiostatic electrolysis could be applied as a new method for estimating the potential distribution in the crevice. [ABSTRACT FROM AUTHOR]

The detection of bacterial deoxyribonucleic acid (DNA) is of great significance in the quality control of food and water. In this study, a light-addressable potentiometric sensor (LAPS) deposited with highly oriented ZnO nanorod arrays (NRAs) was used for the label-free detection of single-stranded bacterial DNA (ssDNA). A functional, sensitive surface for the detection of Escherichia coli (E. coli) O157:H7 DNA was prepared by the covalent immobilization of the specific probe single-stranded DNA (ssDNA) on the LAPS surface. The functional surface was exposed to solutions containing the target E. coli ssDNA molecules, which allowed for the hybridization of the target ssDNA with the probe ssDNA. The surface charge changes induced by the hybridization of the probe ssDNA with the target E. coli ssDNA were monitored using LAPS measurements in a label-free manner. The results indicate that distinct signal changes can be registered and recorded to detect the target E. coli ssDNA. The lower detection limit of the target ssDNA corresponded to 1.0 × 102 colony forming units (CFUs)/mL of E. coli O157:H7 cells. All the results demonstrate that this DNA biosensor, based on the electrostatic detection of ssDNA, provides a novel approach for the sensitive and effective detection of bacterial DNA, which has promising prospects and potential applications in the quality control of food and water. [ABSTRACT FROM AUTHOR]

A light-addressable potentiometric sensor (LAPS) is a chemical sensor with a field-effect structure based on semiconductor. Its response to the analyte concentration is read out in the form of a photocurrent generated by illuminating the semiconductor with a modulated light beam. As stated in its name, a LAPS is capable of spatially resolved measurement using a scanning light beam. Recently, it has been pointed out that a part of the signal current is lost by the return current due to capacitive coupling between the solution and the semiconductor, which may seriously affect the sensor performance such as the signal-to-noise ratio, the spatial resolution, and the sensitivity. In this study, a circuit model for the return current is proposed to study its dependence on various parameters such as the diameter of contact area, the modulation frequency, the specific conductivity of the solution, and the series resistance of the circuit. It is suggested that minimization of the series resistance of the circuit is of utmost importance in order to avoid the influence of the return current. The results of calculation based on this model are compared with experimental results, and its applicability and limitation are discussed. [ABSTRACT FROM AUTHOR]

A light-addressable potentiometric sensor (LAPS) is a semiconductor electrochemical sensor based on the field-effect which detects the variation of the Nernst potential on the sensor surface, and the measurement area is defined by illumination. Thanks to its light-addressability feature, an LAPS-based chemical imaging sensor system can be developed, which can visualize the two-dimensional distribution of chemical species on the sensor surface. This sensor system has been used for the analysis of reactions and diffusions in various biochemical samples. In this review, the LAPS system set-up, including the sensor construction, sensing and substrate materials, modulated light and various measurement modes of the sensor systems are described. The recently developed technologies and the affecting factors, especially regarding the spatial resolution and temporal resolution are discussed and summarized, and the advantages and limitations of these technologies are illustrated. Finally, the further applications of LAPS-based chemical imaging sensors are discussed, where the combination with microfluidic devices is promising. [ABSTRACT FROM AUTHOR]