Application and effectiveness of artificial intelligence for the border management of imported frozen fish in Taiwan

In Taiwan, the number of applications for inspecting imported food has grown annually and noncompliant products must be accurately detected in these border sampling inspections. Previously, border management has used an automated border inspection system (import food inspection (IFI) system) to select batches via a random sampling method to manage the risk levels of various food products complying with regulatory inspection procedures. Several countries have implemented artificial intelligence (AI) technology to improve domestic governmental processes, social service, and public feedback. AI technologies are applied in border inspection by the Taiwan Food and Drug Administration (TFDA). Risk management of border inspections is conducted using the Border Prediction Intelligent (BPI) system. The risk levels are analyzed on based on the noncompliance records of imported food, the country of origin, and international food safety alerts. The subjects of this study were frozen fish products, which have been under surveillance by the BPI system. The purpose of this study was to investigate the relevance between the noncompliant trend of frozen fish products using the adoption of the BPI system and the results of postmarket sampling inspections. The border inspection and postmarket sampling data were divided into two groups: IFI and BPI groups (corresponding to before and after the adoption of the BPI system, respectively). The Chi-square test was employed to analyze the noncompliant differences in products between before and after the BPI system adoption. Despite the number of noncompliance batches being statistically insignificant after the adoption of the BPI system, the noncompliance rate of frozen fish products at the border increased from 3.0% to 4.7%. Meanwhile, the noncompliance rate in the postmarket decreased from 2.1% to 1.9%. The results indicate that the BPI system improves the effectiveness of interception of noncompliant products at the border, thereby preventing the entrance of noncompliant products to the postmarket. The variables were further classified and organized according to the scope of this study and product characteristics. Furthermore, ordinal logistic regression (OLR) was employed to determine the correlations among border, postmarket, and major influencing factors. Based on the analysis of major influencing factors, small fish and fish internal organ products exhibited significantly high risk for fish body type and product type, respectively. The BPI system effectively utilizes the large amount of data accumulated from border inspections over the years. Additionally, real-time information on bilateral data obtained from the border and postmarket should be bidirectionally shared for effectively intercepting noncompliance products and used for improving the border management efficiency.

Prioritization of pesticides in crops with a semi-quantitative risk ranking method for Taiwan postmarket monitoring program

A risk-based prioritization of chemical hazards in monitoring programs allows regulatory agencies to focus on the most potentially concerned items involving human health risk. In this study, a risk-based matrix, with a scoring method using multiple factors for severity and probability of exposure, was employed to identify the pesticides presented in crops that may pose the greatest risk to human health. Both the probability of exposure and the severity were assessed for 91 pesticides detected in a Taiwanese postmarketing monitoring program. Probability of exposure was evaluated based on the probability of consumption and evidence of pesticide residues in crops. Severity was assessed based on the nature of the hazard (i.e., the description of toxic effects), and the acceptable daily intake (ADI) reported by available toxicological reports. This study showed that the nature of the hazard and probability of consumption had the strongest contribution to risk score. Dithiocarbamates, endosulfan, and carbofuran were identified as the pesticides with the highest concern for human health risks in Taiwan. These pesticides should be monitored more frequently than others in crops during the postmarketing monitoring program. However, some uncertainties shall be noted or improved when this methodology is applied for risk prioritization in the future.

Effect of Fullerene Passivation on the Charging and Discharging Behavior of Perovskite Solar Cells: Reduction of Bound Charges and Ion Accumulation

Ion accumulation of organometal halide perovskites (OHPs) induced by electrode polarization of perovskite solar cells (PSCs) under illumination has been intensely studied and associated with a widely observed current-voltage hysteresis behavior. This work is dedicated to the investigation of the behavior of charged species at the compact TiO₂/OHP interface with respect to electrode polarization in PSC devices. By providing a comprehensive discussion of open-circuit voltage ( V_OC) buildup and V_OC decay under illumination and in the dark for the PSCs modified with [6,6]-phenyl-C₆₁ butyric acid methyl ester (PCBM) at the TiO₂/OHP interface and their corresponding electrochemical impedance spectroscopies (EISs), a justified mechanism is proposed attempting to elucidate the dynamics of interfacial species with respect to the time and frequency domains. Our results demonstrate that the retarded V_OC buildup and decay observed in PSC devices are related to the formation of bound charges in TiO₂, which is essential to neutralize the oppositely charged ions accumulating at the OHP side. Besides, inserting a thicker PCBM at the TiO₂/OHP interface as a passivation layer can alleviate the electrode polarization more efficiently as verified by the low dielectric constant measured from EIS. Moreover, photoluminescence measurements indicate that PCBM at the TiO₂/OHP interface is capable of passivating a trap state and improving charge transfer. However, with respect to the time scale investigated in this work, the reduction of the hysteresis behavior on a millisecond scale is more likely due to less bound charge formation at the interface rather than shallow trap-state passivation by PCBM. After all, this work comprehensively demonstrates the interfacial properties of PSCs associated with PCBM passivation and helps to further understand its impact on charging/discharging as well as device performance.

Amino-Acid-Induced Preferential Orientation of Perovskite Crystals for Enhancing Interfacial Charge Transfer and Photovoltaic Performance

Interfacial engineering of perovskite solar cells (PSCs) is attracting intensive attention owing to the charge transfer efficiency at an interface, which greatly influences the photovoltaic performance. This study demonstrates the modification of a TiO₂ electron-transporting layer with various amino acids, which affects charge transfer efficiency at the TiO₂ /CH₃ NH₃ PbI₃ interface in PSC, among which the l-alanine-modified cell exhibits the best power conversion efficiency with 30% enhancement. This study also shows that the (110) plane of perovskite crystallites tends to align in the direction perpendicular to the amino-acid-modified TiO₂ as observed in grazing-incidence wide-angle X-ray scattering of thin CH₃ NH₃ PbI₃ perovskite film. Electrochemical impedance spectroscopy reveals less charge transfer resistance at the TiO₂ /CH₃ NH₃ PbI₃ interface after being modified with amino acids, which is also supported by the lower intensity of steady-state photoluminescence (PL) and the reduced PL lifetime of perovskite. In addition, based on the PL measurement with excitation from different side of the sample, amino-acid-modified samples show less surface trapping effect compared to the sample without modification, which may also facilitate charge transfer efficiency at the interface. The results suggest that appropriate orientation of perovskite crystallites at the interface and trap-passivation are the niche for better photovoltaic performance.

Near-Infrared-Absorbing and Dopant-Free Heterocyclic Quinoid-Based Hole-Transporting Materials for Efficient Perovskite Solar Cells

New heterocyclic quinoid-based hole transporting materials (HTMs) with a rigid quinoid core [3,6-di(2H-imidazol-2-ylidene)cyclohexa-1,4-diene] have been synthesized. The new HTMs have good hole mobility (>10^-4  cm²  V^-1  s^-1 ) and very intense absorption in the near-infrared region extending to >800 nm. High performance perovskite solar cells can be fabricated using these HTMs without dopant. The best cell efficiency under simulated AM 1.5 G illumination reaches 12.22 %, which is comparable with that (12.58 %) using doped 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (spiro-OMeTAD) as the HTM.

Diversity and degradation mechanism of an anaerobic bacterial community treating phenolic wastewater with sulfate as an electron acceptor

Petrochemical wastewater often contains high concentrations of phenol and sulfate that must be properly treated to meet discharge standards. This study acclimated anaerobic-activated sludge to treat saline phenolic wastewater with sulfate reduction and clarified the diversity and degradation mechanism of the microbial community. The active sludge in an upflow anaerobic sludge blanket (UASB) reactor could remove 90 % of phenol and maintain the effluent concentration of SO4 (2-) below 400 mg/L. Cloning and sequencing showed that Clostridium spp. and Desulfotomaculum spp. were major phenol-degrading bacteria. Phenol was probably degraded through the carboxylation pathway and sulfate reduction catalyzed by adenosine-5'-phosphosulfate (APS) reductase and dissimilatory sulfite reductase (DSR). A real-time polymerase chain reaction (RT-PCR) showed that as phenol concentration increased, the quantities of 16S rRNA gene, dsrB, and mcrA in the sludge all decreased. The relative abundance of dsrB dropped to 12.46 %, while that of mcrA increased to 56.18 %. The change in the electron flow ratio suggested that the chemical oxygen demand (COD) was removed mainly by sulfate-reducing bacteria under a phenol concentration of 420 mg/L, whereas it was removed mainly by methanogens above 630 mg/L.

Tunable slow light device using quantum dot semiconductor laser

This investigation experimentally demonstrates a tunable slow light device using a quantum dot (QD) semiconductor laser. The QD semiconductor laser at 1.3 mum fabricated on a GaAs substrate is grown by molecular beam epitaxy. Tunable slow light can be achieved by adjusting the bias current and wavelength detuning. The slow light device operated under probe signal from 5 to 10 GHz is presented. Moreover, we also demonstrate that the tunable slow light device can be used in a subcarrier multiplexed system.

Dynamic characteristics of long-wavelength quantum dot vertical-cavity surface-emitting lasers with light injection

This investigation experimentally demonstrates the dynamic characteristics of quantum dot vertical-cavity surface-emitting lasers (QD VCSEL) without and with light injection. The QD VCSEL is fully doped structure on GaAs substrate and operates in the 1.3 mum optical communication wavelength. The eye diagram, frequency response, and intermodulation distortion are presented. We also demonstrate that the frequency response enhancement by light injection technique allows us to improve the performance of subcarrier multiplexed system.

Magnolol, a potent antioxidant from Magnolia officinalis, attenuates intimal thickening and MCP-1 expression after balloon injury of the aorta in cholesterol-fed rabbits

BACKGROUND

Restenosis is a common complication after balloon angioplasty. A number of cytokines, chemotactic factors and growth factors may be involved. Several antioxidants have been shown to inhibit intimal thickening after balloon injury in hyperlipidemic animals.

OBJECTIVES

The effects of magnolol on the expression of monocyte chemotactic protein-1 (MCP-1) and intimal response in balloon injured aorta of cholesterol-fed rabbits were investigated.

METHODS

Male New Zealand white rabbits were fed a 2% high cholesterol (HC) diet together with daily intramuscular injection of either 1 microg/kg B.W. of magnolol (HC-M, n = 10) or vehicle (propylene glycol) as a control (HC-C, n = 10) for a total of 6 weeks. Another 10 rabbits fed a regular diet also served as a control (C) group. A balloon denudation of abdominal aorta was performed in each group at the end of the third week. The aortas were harvested at the end of 6 weeks.

RESULTS

Magnolol treatment significantly inhibited Cu2+-induced LDL oxidation in cholesterol-fed rabbits and reduced atheroma formation [atheroma area ratio: 0.10 +/- 0.03 (HC-M) versus 0.33 +/- 0.07 (HC-C), p < 0.05] in thoracic aortas without lowering serum cholesterol. The intimal response was significantly attenuated in the HC-M rabbits when compared to those of the HC-C group [intimal thickness: 88.95 +/- 14.91 microm (HC-M) versus 198.02 +/- 20.35 microm (HC-C), p < 0.05; intimal area: 278.21 +/- 43.16 x 10(3) microm2 (HC-M) versus 642.70 +/- 65.01 x 10(3) microm2 (HC-C), p < 0.05]. The MCP-1 mRNA and protein expression were reduced in the HC-M group compared to the HC-C and C groups.

CONCLUSION

The inhibitory effects on intimal hyperplasia and MCP-1 expression might be attributed to the antioxidant capacity of magnolol instead of lowering serum cholesterol. Magnolol may offer some protection against postangioplasty restenosis.