Colorimetric Sensor Array for Monitoring CO and Ethylene

摘要： Developing miniaturized and inexpensive detectors remains an important and practical goal for field-deployable monitoring of toxic gases and other bioactive volatiles. CO (a common toxic pollutant) and ethylene (the phytohormone primarily responsible for fruit ripening) share the capability of strong back-π-bonding to low-oxidation-state metal ions, which has proved important in the development of metal-ion-based sensors for these gases. We report herein cumulative colorimetric sensor arrays based on Pd(II)-silica porous microsphere sensors and their application as an optoelectronic nose for rapid colorimetric quantification of airborne CO and ethylene. Quantitative analysis of two gases was obtained in the range of 0.5 to 50 ppm with detection limits at the sub-parts-per-million level (～0.4 ppm) after 2 min of exposure and ～0.2 ppm after 20 min (i.e., <0.5% of the permissible exposure limit for CO and <10% of the ethylene concentration needed for fruit ripening). We further validate that common potential interfering agents (e.g., changes in humidity or other similar air pollutants such as NOx, SO2, H2S, or acetylene) are not misidentified with CO or ethylene. Finally, the sensor is successfully used for the quantification of ethylene emitted from ripening bananas, demonstrating its potential applications in the monitoring of fruit ripening during storage.

New, sensitive behavioral assay shows scorpions are attracted to multiple wavelengths of light

摘要： Scorpions ?uoresce a bright green when under ultraviolet light, but the functional signi?cance of the ?uorescence is still unknown. A major challenge in studying scorpion ?uorescence is the lack of ef?cient methods for testing the behavioral photosensitivity of scorpions. We have modi?ed previous assays to produce a more sensitive testing device. The apparatus consists of a circular track made of a small Petri dish nested inside a larger one, with an LED shining from the inner chamber across a small sector of the track. We monitored the scorpions’ movements in the arenas under three light wavelengths: ultraviolet (399 nm), yellow-green (566 nm), and red (630 nm); all wavelengths were matched to a nighttime light intensity (0.01 irradians). We also tracked each animal’s movements in the absence of light as a control. The animals were attracted to 399 and 566 nm light and also showed some attraction to 630 nm. Furthermore, earlier studies suggest that scorpion photoreceptors form a homogeneous population that has been physiologically shown to be maximally sensitive to green wavelengths. We hypothesize that the photoreceptor population might be somewhat responsive to red light too, suggesting that the photoreceptors may respond to a broad spectrum of light or that the photoreceptor population may not be as homogeneous as previously thought. The strong response to UV light, as has been seen in other behavioral assays, remains enigmatic. Overall, this new assay is more sensitive than previous assays for detecting scorpion photoresponse and will be useful for future studies.

Implementation of Plateau Histogram Equalization Technique on Thermal Images

Dual?Wavelength Ratiometric Electrochemiluminescence Immunosensor for Cardiac Troponin I Detection

摘要： Ratiometric electrochemiluminescence (ECL) has attracted special focus in biological analysis field because it could eliminate the environmental interference to gain precise measurement. Herein, a dual?wavelength ratiometric ECL biosensor was designed for detection of cardiac troponin I (cTnI), where (4,4’?dicarboxylicacid?2,2’?bipyridyl) ruthenium(II) (Ru(dcbpy)3 2+) and Au nanoparticles loaded graphene oxide/polyethyleneimine (GPRu?Au) nanomaterial acts as an acceptor, and Au nanoparticles modified graphitic phase carbon nitride nanosheets composite (Au?CNN) acts as donor. Au?CNN shows high and steady ECL signal centered at 455 nm, which is well matched with the adsorption of GPRu?Au, thereby a high efficient electrochemiluminescent resonance energy transfer (ECL?RET) sensing platform is designed. AuNPs facilitate the immobilization of antibody on the nanomaterials through Au?N bond. The high surface area of graphene oxide/polyethyleneimine allows a large number of Ru(dcbpy)3 2+ to be loaded, which immensely amplify the ECL signal. This sensing platform exhibits outstanding analytical performance toward cTnI with a detection limit of 3.94 fg/mL (S/N=3). The high reliability, selectivity and sensitivity of this ratiometric ECL biosensor provides a versatile sensing platform for the bioanalysis.

Pest Control Lamp in Green Food Bases Based on Wind-solar Complementary Generation System

摘要： According to the energy complementary characteristics of wind energy and solar energy in time and space, in this study, the wind turbine and solar cells are used to design a pest control lamp in green food bases powered by a small power wind-solar complementary supply system and the intelligent controller is used to charge and discharge the batteries, realizing various protection functions. Application shows that the pest control lamp in green food bases system has the advantages of low manufacturing cost and high reliability, suitable for being used in farmland and woodland which are far from the grid.

Dual-Channel Photoelectrochemical Ratiometric Aptasensor with Up-converting Nanocrystals Using Spatial-Resolved Technique on Homemade 3D Printed Device

摘要： A near-infrared light (NIRL)-activated ratiometric photoelectrochemical (PEC) aptasensor was fabricated for detection of carcinoembryonic antigen (CEA) coupling with upconversion nanoparticles (UCNPs)-semiconductor nanocrystals-based spatial-resolved technique on a homemade 3D printing device in which a self-regulating integrated electrode was designed for dual signal readout. The as-prepared NaYF4:Yb, Er UCNPs@CdTe nanocrystals were initially assembled on two adjacent photoelectrodes, then CEA aptamer 1 (A1) and capture DNA (CA) were modified onto two working photoelectrodes (WP1 and WP2) through covalent binding, respectively, and then gold nanoparticle-labeled CEA aptamer 2 (Au NP-A2) were immobilized on the surface of functional WP2 for the formation of double-stranded DNA. Upon target CEA introduction, the various concentrations of CEA were captured on the WP1, whereas the binding of the CEA with Au NP-A2 could be released from the WP2 thanks to the highly affinity of CEA toward A2. The dual signal readout with the 'signal-off' of WP1 and 'signal-on' of WP2 were employed for the spatial-resolved PEC (SR-PEC) strategy to detect CEA as an analytical model. Combining NaYF4:Yb, Er UCNPs@CdTe nanocrystals with spatial-resolved model on 3D printing device, the PEC ratiometric aptasensor based on steric hindrance effect and exciton-plasmon interactions (EPI) exhibited a linear range from 10.0 pg mL-1 to 5.0 ng mL-1 with a limit of detection of 4.8 pg mL-1 under 980 nm illumination. The SR-PEC ratiometric strategy showed acceptable stability and reproducibility with a superior anti-interference ability. This approach can provide the guidance for the design of ratiometric, multiplexed and point-of-care biosensors.

Research and Development Work on Solar Assisted Drying Systems

摘要： The solar energy research group from Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia (UKM) has designed and constructed solar assisted drying systems for drying agricultural and marine products. This study is a review of numerous types of solar dryer systems developed by SERI, UKM. The classification of solar drying systems has divided by two namely air based solar collector systems and water based solar collector systems. Drying with solar assisted drying systems was found to be a viable option with many benefits such as protected drying environment, improved dried quality of products and reduces drying time compared with the traditional sun drying method. Therefore, SERI’s solar assisted drying system shows a great potential for application in drying process of agricultural and marine products.

Counteranion-Triggered and Excitation-Dependent Chemopalette Effect in a Supramolecular Dual-Emissive System Based on Cu <sub/>3</sub> Pz <sub/>3</sub>

摘要： Three Cu3Pz3-based isostructural complexes (Cu3L3)2(CuX)2 (labeled as 1-ClO4, 1-NO3, and 1-Br, where X = ClO4?, NO3?, and Br?, respectively) were prepared by solvothermal reactions of an angular bifunctional pyridyl?pyrazole ligand, 4-(pyridin-4′-ylthio)-3,5-dimethyl-1H-pyrazole (HL), with Cu(ClO4)2, Cu(NO3)2, and CuBr, respectively. Pyrazolate (Pz) groups are highly specific to form planar trinuclear Cu3Pz3 units. Two Cu3L3 units are further connected by two CuX units through NPy?Cu?NPy (Py = 4-pyridyl) bonds to form an octanuclear chairlike molecule (Cu3L3)2(CuX)2, which then self-assembles through intertrimeric cuprophilicity to construct chainlike supraaggregates featuring two luminophores, [Cu3Pz3]2 and CuPy2X. With different counteranions (ClO4?, NO3?, and Br?), the complexes give off various emissions from red to green upon UV irradiation. 1-ClO4 and 1-NO3 show only low-energy (LE) orange (λemmax = 585 nm) and red (λemmax = 640 nm) emissions, while 1-Br exhibits excitation-dependent (260?360 nm) emissions from yellow to green due to variation in the relative intensities of two resolvable emissions, high energy (HE, λemmax = 520 nm) and LE (λemmax = 630 nm). The dual emissions are assigned to 3CC (LE states) based on excimeric [Cu3Pz3]2 units and 3XLCT/3MLCT (HE states) based on CuPy2X units. This work realizes a chemopalette effect through regulations of the counteranion and excitation energy in a dual-emissive system. It provides valuable insights into the nature of dual-emissive materials and the further investigation of the photophysical mechanism in such a system.

Single flash electroretinograms of mature cataractous and fellow eyes

摘要： Background: It is generally stated that opacities of the ocular media, including senile cataract, have little effect on the electrical responses of the retina. However, lower amplitudes and longer implicit times are sometimes observed in electroretinograms (ERGs) of patients with mature cataract. Methods: Single flash ERGs of mature cataractous eyes with decimal visual acuity less than 0.1 were compared with those of the fellow eyes with decimal visual acuity better than 0.5, in 105 senile cataract patients. Results: The mean amplitudes and implicit times of ERG a-waves were, respectively, 323.6±95.8 μV and 14.7±3.5 ms in the cataractous eyes and 352.3±96.6 μV and 12.0±1.5 ms in the fellow eyes. The mean amplitudes and implicit times of ERG b-waves were, respectively, 390.1±108.7 μV and 63.4±27.9 ms in the cataractous eyes and 415.3±119.1 μV and 59.0±9.3 ms in the fellow eyes. The mean amplitudes of the a- and b-waves were significantly lower and the mean implicit times of the a- and b-wave were significantly longer in the cataractous eyes as compared to those of the fellow eyes. Postoperative visual acuity was similar in cataractous and fellow eyes. Conclusion: Even though single flash ERG was influenced due to mature cataract, eyes revealed good postoperative visual acuity. Single flash ERG does not always reflect the foveal function and the visual pathway; nevertheless, it remains a reliable guide to evaluate visual prognosis before cataract surgery.

Spectral domain optical coherence tomography imaging of subretinal bands associated with chronic retinal detachments

摘要： We report three patients with subretinal bands associated with retinal detachment in chronic retinal detachments who underwent successful retinal reattachment. Subretinal bands before and after surgery can be identified on clinical examination and spectral domain optical coherence tomography. Removal of subretinal bands is not mandatory to achieve retinal reattachment.