Bioactive metabolite profiles and quality of Rosa rugosa during its growing and flower-drying process.

Rosa rugosa is extensively cultivated in China for its remarkable fragrance and flavor, however, the metabolic changes in roses during growth and drying remain unclear. Our results revealed significant variations in phenol and flavonoid contents and antioxidant capacity in roses (Rosa rugosa f. plena (Regel) Byhouwer) under different conditions. Phenol contents were positively correlated with antioxidant capacity, with phytochemicals being most prominent in unfolded petals. The highest antioxidant capacity and phenol and flavonoid contents were observed in April. Considering their greater consumption value, whole flowers were more suitable than petals alone. Furthermore, considerable sensory and nutritional differences were observed in dried roses. Different drying methods increased their total phenol content of roses by 4.2-5.4 times and the antioxidant capacity by 2.9 times. Metabolomics revealed the altered contents of flavonoids, anthocyanins, lipids, amino acids, and saccharides. This study provides baseline data for the potential of roses as a natural source of antioxidants in the food and pharmaceutical industries.

Residue behaviors, processing factors and transfer rates of pesticides and metabolites in rose from cultivation to consumption.

The presence of pesticide residues in rose makes it necessary to pay special attention to the proper cultivation to consumption. In this study, the inherent regularity of residue behaviors, processing factors and transfer rates of pesticides and potential metabolites during rose planting, drying and brewing was researched. The half-lives in the bud, corolla and leaf were 0.5-2.9, 0.3-1.7 and 2.6-25.9 d, respectively. Residues were more distributed in leaf, followed by corolla, bud and root. Systemic pesticides could appear in the root 1 day after application, and non-systemic pesticides were not detected in the root. The effect of sun and oven drying (80 °C) was more significant in promoting the degradation of cyazofamid, bifenazate, thiamethoxam and imidacloprid. The processing factors (PFs) of other pesticides were > 1. Our results showed that the transfer rate of residues during brewing was negatively correlated exponentially with Log Kow and positively logarithmically correlated with melting point and water solubility. The transfer rate of residues and antioxidant capacity in infusion were significantly affected by different brewing conditions.

Achievable Rate Maximization for Multi-Relay AF Cooperative SWIPT Systems with a Nonlinear EH Model.

In this paper, the maximization of the achievable information rate is proposed for the multi-relay amplify-and-forward cooperative simultaneous wireless information and power transfer communication systems, where the nonlinear characteristic of the energy harvesting (EH) circuits is taken into account for the receivers of the relay nodes. The time switching (TS) and power splitting (PS) schemes are considered for the EH receivers and the achievable rate maximization problems are formulated as convex and non-convex optimization problems, respectively. The optimal TS and PS ratios for the relay nodes along with the maximum achievable rates for the system are obtained, respectively, by solving the optimal problems with efficient algorithms. The asymptotic maximum achievable rates at low and high input signal-to-noise ratios (SNRs) for both the PS and TS schemes are also analyzed. It is demonstrated that the PS scheme is more susceptible to the variation of the relays' location and the channel parameters than TS scheme, whereas the TS scheme is more susceptible to the mismatch of the resource allocation than PS scheme. Specifically, compared to the linear EH model, the nonlinear EH model achieves significant performance gain for the TS scheme, whereas inconspicuous performance improvement is achieved for the PS scheme.

Residue distribution and risk assessment of bifenazate and its metabolite in garlic plant.

The dissipation, conversion and risk assessment of bifenazate and bifenazate-diazene in garlic plant were studied by a modified QuEChERS method coupled with UHPLC-MS/MS for the first time. Bifenazate dissipated rapidly in garlic chive and serpent garlic with the half-lives of 3.0-3.9 days and 6.1-6.9 days, respectively. Bifenazate residue on garlic (<0.01 mg/kg) was significantly lower than the other two matrices in the whole growing period, which meant residues in the above-ground part were not transferred to the garlic. Furthermore, garlic chive had higher residues than serpent garlic due to the differences in morphological characteristics. Bifenazate-diazene was easier to convert to bifenazate, with the conversion rates of 93%, 16% and 32% in garlic, serpent garlic and garlic chive extracts, respectively. Additionally, the dietary intake risk for bifenazate was acceptable with RQchronic < 100% according to the international and national assessments.

Determination, residue analysis, dietary risk assessment, and processing of flupyradifurone and its metabolites in pepper under field conditions using LC-MS/MS.

An effective method based on LC-MS/MS was established to determine the concentrations of flupyradifurone, difluoroacetic acid, and 6-chloronicotinic acid in pepper. On the basis of this method, the dissipation, processing factor, and dietary risk of flupyradifurone in pepper were investigated. The results show that the half-life of flupyradifurone in peppers was 2.6-3.8 days. The terminal residual concentration of flupyradifurone in the supervised trials was not higher than the maximum residue limit (MRL) for pepper in the Codex Alimentarius Commission (CAC) (0.9 mg kg-1 ) with the highest residual values of 0.53 mg kg-1 . The national estimated daily intake of flupyradifurone was 0.00094 mg kg-1 , based on the dietary structure of Chinese consumers and the terminal residues under field conditions. The risk quotient for flupyradifurone was 0.012, which was significantly < 1. The processing factor of flupyradifurone in dried pepper was 10.9-14.2, which indicated that drying increased the residual amounts of flupyradifurone in dried pepper, but the residual concentration was still lower than its MRL of 9 mg kg-1 established by CAC.

Performance Analysis for SWIPT Cooperative DF Communication Systems with Hybrid Receiver and Non-Linear Energy Harvesting Model.

In this paper, we study the outage and throughput performance for the simultaneous wireless information and power transfer (SWIPT) cooperative decode-and-forward (DF) communication systems. The hybrid receiver that uses both time switching (TS) and power splitting (PS) methods for energy harvesting (EH) and information decoding (ID), and the piece-wise linear EH model that captures the non-linear input-output characteristic of the EH circuit, are considered. We present exact analytical expressions of the outage probability (OP) and throughput, which are expressed as single definite integral on finite interval and can be easily evaluated, for the systems in Rayleigh fading channel. For further simplicity of calculation, we derive novel and closed-form approximate expressions of the OP and throughput. The impact of different system parameters on the system performance is investigated. Numerical results show the high accuracy of the proposed closed-form approximate expressions especially in the region of higher signal-to-noise ratio (SNR). It is also shown that the system performance is greatly overestimated when the ideal linear EH model is used instead of the practical non-linear EH model. A different result to the non-hybrid receiver with both linear EH model and non-linear EH model that there exists an optimal location to minimize the OP for the hybrid receiving relay node with non-linear EH model is also demonstrated.