Set of mathematical models for Bessel-Gauss beams coupling into the parabolic-index fiber under the influence of atmospheric turbulence and random jitter.

The expression of efficiency for Bessel-Gauss (BG) beams coupling into the parabolic fibers (PF) after passing through the Cassegrain antenna system is first derived. The effects of atmospheric turbulence and random jitter of the coupling lens on the efficiency are also taken into account to improve the practical applicability of our model. This article use a BG beam with a wavelength of 1550 mm and fiber with a core radius RF of 50 µm and a relative refractive index difference ζ of 0.01 for simulation testing. The optimal parameters of the antenna system are determined: the radius of the primary mirror and the secondary mirror is 8.33 cm and 1.25 cm, respectively. The coupling efficiency of BG beams of different orders reaches above 94% simultaneously when the lens's focal length is 7.8 cm. After taking into account the transmission efficiency of the antenna system, the system's total efficiency for BG beams of different orders averages 76.33%, when the transmission distance is 1 km. The results show that the same degree of turbulence and random jitter have different influences on the coupling efficiency of BG beams of different orders, and lower-order BG beams have better resistance to turbulence and jitter during propagation and coupling. Moreover, the effect of the guided mode field on the coupling efficiency and the resistance to turbulence varies for different values of mode radial index in the fiber p. The guided mode with p = 0 not only enables the BG beams of different orders to achieve the highest transmission efficiency in the coupling system almost simultaneously but also the random jitter and turbulence have less influence on the coupling efficiency of this mode. It means that the BG beams can have higher efficiency when coupled to the mode with p = 0 after long-distance transmission. This property of the fiber mode at p = 0 provides conditions for the simultaneous propagation of multiple BG beams in a parabolic fiber, which provides a theoretical basis for higher transmission capacity. This research work provides a theoretical model for the theoretical study of vortex beams and optical communication, which is beneficial for the design and application of vortex beams and has instructive meaning for practical engineering design.

Target and suspect screening of pesticide residues in soil samples from peach orchards using liquid chromatography quadrupole time-of-flight mass spectrometry.

Agricultural soil contamination by pesticide residues has become a serious issue of increasing concern due to their high persistence and toxicity to non-target species. However, as the world's largest peach producer, national scale surveys on pesticide residues in peach orchard soils are scarce in China. In this study, a target and suspect screening method covering over 200 pesticides commonly used in peach orchards was developed using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry in MSE. An identification strategy using different data processing parameters was developed to identify the pesticide occurrence in soil. The method was applied to soil samples from typical peach orchards in 12 regions across China. The present work also discusses in detail the frequency of occurrence, concentration of pesticides, spatial distribution of multiresidues, and relationship between pesticide occurrence and soil properties. In the tested soil samples, 21 herbicides (level 1), 31 fungicides (level 2a), 24 insecticides (level 2a), and 3 growth regulators (level 2a) were identified. The total concentrations of quantifiable herbicides in the soil samples ranged from 1.05 to 327 ng/g. Only in 5.4% of the soil samples, no pesticide residues were present. By contrast, more than 86% of the total contained multiple residues. This study represents the first large-scale survey of pesticides in soil from peach orchards and provides comprehensive and accurate information on the pesticide residue status for risk assessment.

Gastrodin alleviates perioperative neurocognitive dysfunction of aged mice by suppressing neuroinflammation.

Perioperative neurocognitive disorder (PND) is a common complication of elderly patients after surgery and lacks effective prevention and treatment measures. We investigated the effect and mechanism of gastrodin (GAS), a natural plant ingredient, on postoperative cognition induced by laparotomy in aged mice. Male aged (18 months) mice were subjected to laparotomy and orally treated with GAS (25, 50, and 100 mg/kg) 3 weeks before surgery and 1 week after surgery. In addition, some male aged (18 months) mice were subjected to viral vector or GSK-3ß expression virus injection followed by laparotomy with or without 100 mg/kg GAS treatment. GAS improved learning and memory in aged mice after surgery. Surgery increased the levels of pro-inflammatory factors (TNF-α, IL-1ß and IL-6) and decreased the level of an anti-inflammatory factor (IL-10) in the mouse hippocampus, and these changes were reversed by GAS treatment. GAS also suppressed the activation of microglia. GAS inhibited the phosphorylation of GSK-3ß and Tau. Furthermore, surgery induced more serious cognitive dysfunction, inflammatory factors, activation of microglia, and phosphorylation of GSK-3ß and Tau in GSK-3ß overexpressing aged mice. The improvement of learning and memory, the reduction of inflammation and microglia activation, and the suppression of GSK-3ß and Tau phosphorylation by GAS were prevented when GSK-3ß was overexpressed in aged mice subjected to surgery. Our finding suggested that GAS exerts neuroprotective effects in aged mice subjected to laparotomy by suppressing neuroinflammation and GSK-3ß and Tau phosphorylation. Thus, these findings suggest that GAS may be a promising agent for PND.

Estrogen prevent atherosclerosis by attenuating endothelial cell pyroptosis via activation of estrogen receptor α-mediated autophagy.

Excessive inflammation and the pyroptosis of vascular endothelial cells caused by estrogen deficiency is one cause of atherosclerosis in post-menopausal women. Because autophagy is highly regulated by estrogen, we hypothesized that estrogen can reduce vascular endothelial cell pyroptosis through estrogen receptor alpha (ERα)-mediated activation of autophagy to improve atherosclerosis in post-menopausal stage. Aortic samples from pro-menopausal and post-menopausal women with ascending aortic arteriosclerosis were analyzed, and bilateral ovariectomized (OVX) female ApoE-/- mice and homocysteine (Hcy)-treated HUVECs were used to analyze the effect of estrogen supplementation therapy. The aortic endothelium showed a decrease in ERα expression and autophagy, but presented an increase in inflammation and pyroptosis in female post-menopausal patients. Estrogen treatment accelerated autophagy and ameliorated cell pyroptosis in the cardiac aortas of OVX ApoE-/- mice and Hcy-treated HUVECs. Estrogen had therapeutic effect on atherosclerosis and improved the symptoms associated with lipid metabolism disorders in OVX ApoE-/- mice. Inhibition and silencing of ERα led to a reduction in the autophagy promoting ability of estrogen and aggravated pyroptosis. Moreover, the inhibition of autophagy promoted pyroptosis and abolished the protective effect of estrogen, but had no influence on ERα expression. Thus, the results of the present study demonstrated that post-menopausal women present decreased autophagy and ERα expression and excessive damage to the ascending aorta. In addition, in vitro and in vivo assay results demonstrated that estrogen prevents atherosclerosis by upregulating ERα expression and subsequently induces autophagy to reduce inflammation and pyroptosis.

Dexmedetomidine effect on delirium in elderly patients undergoing general anesthesia: A protocol for systematic review and meta-analysis.

BACKGROUND: Delirium is a common postoperative complication. Many studies have found that dexmedetomidine is associated with a reduced incidence of postoperative delirium (POD). This meta-analysis aimed to analyze the effects of dexmedetomidine on POD incidence among elderly patients undergoing general anesthesia. METHODS: We searched 4 electronic databases (i.e., Pubmed, Embase, Cochrane, and Web of Science) from inception to November 30, 2020, for randomized controlled trials that evaluated the effects of dexmedetomidine in preventing the occurrence of POD in elderly patients (aged ≥60 years). The study protocol was registered in PROSPERO (CRD42020192114). RESULTS: 14 studies with 4173 patients showed that dexmedetomidine was significantly associated with a decreased POD incidence among elderly patients (relative risk [RR] = 0.58; 95% confidence interval [CI] = 0.44-0.76). The incidence of POD was significantly reduced in the noncardiac surgery group (RR 0.51; 95% CI 0.37-0.72), when dexmedetomidine was applied during the postoperative period (RR = 0.53; 95% CI = 0.40-0.70), and in patients received low-doses (RR = 0.54; 95% CI = 0.34-0.87) and normal-doses (RR = 0.59; 95% CI = 0.42-0.83). There were no significant differences in POD incidence in the cardiac surgery group (RR = 0.71; 95% CI = 0.45-1.11), and when dexmedetomidine was applied during the intra- (RR = 0.55; 95% CI = 0.29-1.01) or perioperative period (RR = 0.95; 95% CI = 0.64-1.40). CONCLUSIONS: Our meta-analysis suggests that dexmedetomidine may significantly reduce POD incidence in elderly noncardiac surgery patients and when applied during the postoperative period, in addition, both low- and normal-doses of dexmedetomidine may reduce POD incidence. However, its use in cardiac surgery patients and during the intra- or perioperative period may have no significant effects on POD incidence.