An extensive evaluation of low-cost dust sensors was performed using an exponentially decaying particle concentration. A total of 264 sensors including 27 sensors with light-emitting diodes (LEDs) and 237 sensors with laser lighting sources were tested. Those tested sensors were classified into 4 groups based on the deviation from the reference data obtained by a reference instrument. The response linearities of all the tested samples for PM1, PM2.5, and PM10 were in excellent agreement with the reference instrument, except a few samples. For the measurements of PM1 and PM2.5, the lighting source, that is, LED or laser, did not show any significant difference in overall sensor performance. However, LED-based sensors did not perform well for PM10 measurements. The 32, 24, and 16% of all the tested sensors for PM1, PM2.5, and PM10 measurement, respectively, are in the category of Class 1 (reference instrument reading ± 20%) requirement. The performance of the low-cost dust sensors for PM10 measurement was relatively less satisfactory. 相似文献
Lipoxins (LXs) are autacoids, specialized proresolving lipid mediators (SPMs) acting locally in a paracrine or autocrine fashion. They belong to a complex superfamily of dietary small polyunsaturated fatty acid (PUFA)–metabolites, which direct potent cellular responses to resolve inflammation and restore tissue homeostasis. Together, these SPM activities have been intensely studied in systemic inflammation and acute injury or infection, but less is known about LX signaling and activities in the central nervous system. LXs are derived from arachidonic acid, an omega‐6 PUFA. In addition to well‐established roles in systemic inflammation resolution, they have increasingly become implicated in regulating neuroinflammatory and neurodegenerative processes. In particular, chronic inflammation plays a central role in Alzheimer's disease (AD) etiology, and dysregulated LX production and activities have been reported in a variety of AD rodent models and clinical tissue samples, yet with complex and sometimes conflicting results. In addition, reduced LX production following retinal injury has been reported recently by the authors, and an intriguing direct neuronal activity promoting survival and homeostasis in retinal and cortical neurons is demonstrated. Here, the authors review and clarify this growing literature and suggest new research directions to further elaborate the role of lipoxins in neurodegeneration. 相似文献
Scientometrics - Science funders are increasingly requiring evidence of the broader impacts of even basic research. Initiatives such as NIH’s CTSA program are designed to shift the research... 相似文献
The number of infertile couples considering using assisted reproductive technologies (ARTs) is growing. Several key indices, such as sperm concentration and motility, are considered when determining an appropriate technique among the existing ARTs. While microscopy is the only way to observe sperms, this method tends to overlook the actual swimming ability of sperms because sperms can be observed only within a very narrow field of view (FOV). In this paper, we propose a microfluidic chip capable of measuring the motility of sperms by inducing the actual swimming ability of sperms in microchannels. To determine whether sperms swim by themselves and reach the target point, 5–10 min is required in an incubator at 37 °C, which inevitably causes the evaporation of the fluid at the microfluidic chip inlet or outlet. A unique structure has been added to the microfluidic chip to prevent unwanted fluid flow due to evaporation, and counting and sorting capabilities of the fabricated device have been experimentally demonstrated. The microfluidic chip is shown to have a good agreement with commercial chips in total sperm counting. Another feature of sorting motile and progressive sperm to 95% on one chip is also verified. This feature differentiates our solution from the existing commercial chips and can help increase the success rate of ARTs. The developed MFC can provide a way to determine the actual swimming motility of sperms using a microscope in small clinics or a portable kit which is publicly available without the expensive sperm analysis equipment.
Effects of operating parameters in the thermal gradient chemical vapor infiltration of propane such as thermal gradient, diffusion, infiltrations time, and concentration of propane were studied by focusing on the visualizations of the intrinsic effects of these parameters. A uniform deposition in the preform was obtained with a gradually increasing temperature along the gas flow. The uniformity of deposition through the preform got improved with increasing deposition time. Results of numerical modeling estimated the experimental data very well when the pre-exponential factor of the overall rate of carbon deposition from propane reported by Vaidyaraman[1] was multiplied by 4. The average density of a preform increased by about 3 times from 0.38 to 1.15 g/cm3 after 60 hr deposition with a thermal gradient under the conditions of 3% propane in nitrogen and 840 to 900 ℃. 相似文献
This work demonstrates a means of automatic transformation from planar electronic devices to desirable 3D forms. The method uses a spatially designed thermoplastic framework created via extrusion shear printing of acrylonitrile–butadiene–styrene (ABS) on a stress‐free ABS film, which can be laminated to a membrane‐type electronic device layer. Thermal annealing above the glass transition temperature allows stress relaxation in the printed polymer chains, resulting in an overall shape transformation of the framework. In addition, the significant reduction in the Young's modulus and the ability of the polymer chains to reflow in the rubbery state release the stress concentration in the electronic device layer, which can be positioned outside the neutral mechanical plane. Electrical analyses and mechanical simulations of a membrane‐type Au electrode and indium gallium zinc oxide transistor arrays before and after transformation confirm the versatility of this method for developing 3D electronic devices based on planar forms. 相似文献
Multimedia Systems - The preferences of Web information purchasers are changing. Cost-effectiveness (i.e., an emphasis on performance with respect to price) is becoming less regarded than... 相似文献
Maintaining a vacuum between the two glasses to maximize the heat insulating performance, it is indispensable to array the pillar for the vacuum glazing to maintain the vacuum gap. In this paper, to investigate the effect of the spacing of the pillars arranged using the screen printing method on the strength of the glass, a bending strength test was carried out by design and fabricating a ROR bending strength test jig based on the Euro standard. In the strength test results, the experimental results were analyzed using the Weibull distribution, which is a statistical analysis method mainly used for evaluating the breaking strength of brittle material. Based on the analysis results, the placement spacing of the pillars proved validity for maintaining the vacuum glass gaps. 相似文献