Interleukin-6 triggers human cerebral endothelial cells proliferation and migration: The role for KDR and MMP-9

Interleukin-6 (IL-6) is involved in angiogenesis. However, the underlying mechanisms are unknown. Using human cerebral endothelial cell (HCEC), we report for the first time that IL-6 triggers HCEC proliferation and migration in a dose-dependent manner, specifically associated with enhancement of VEGF expression, up-regulated and phosphorylated VEGF receptor-2 (KDR), and stimulated MMP-9 secretion. We investigated the signal pathway of IL-6/IL-6R responsible for KDR's regulation. Pharmacological inhibitor of P13K failed to inhibit IL-6-mediated VEGF overexpression, while blocking ERK1/2 with PD98059 could abolish IL-6-induced KDR overexpression. Further, neutralizing endogenous VEGF attenuated KDR expression and phosphorylation, suggesting that IL-6-induced KDR activation is independent of VEGF stimulation. MMP-9 inhibitor GM6001 significantly decreases HCEC proliferation and migration (p < 0.05), indicating the crucial function of MMP-9 in promoting angiogenic changes in HCECs. We conclude that IL-6 triggers VEGF-induced angiogenic activity through increasing VEGF release, up-regulates KDR expression and phosphorylation through activating ERK1/2 signaling, and stimulates MMP-9 overexpression. (c) 2006 Elsevier Inc. All rights reserved

Effects Of Nitrogen Dioxide On Allergic Airway Responses In Subjects With Asthma

Objective: We sought to determine whether nitrogen dioxide (NO2) can enhance airway inflammation after allergen challenge in asthmatic subjects. Methods: Fifteen house-dust-mite (HDM)-sensitive asthmatic subjects were exposed for 3 hours to filtered air or 0.4 ppm NO2, followed by inhalational challenge with HDM allergen. Markers of inflammation were measured in sputum at 6 hours and 26 hours after allergen challenge. Results: After exposure to NO2, eosinophil concentration decreased significantly in the 6-hour postallergen sputum. No significant NO2-related difference was observed for other variables. Conclusions: Our results suggest that, in most asthmatic individuals, multihour exposure to a high ambient concentration of NO2 does not enhance the inflammatory response to subsequent inhaled allergen as assessed by cell distribution in induced sputum. Because the decrease in airway eosinophils has been reported in previous animal studies, future research should be directed toward the mechanism of this effect

Lightweight Detection Algorithm of Kiwifruit Based on Improved YOLOX-S

Considering the high requirements of current kiwifruit picking recognition systems for mobile devices, including the small number of available features for image targets and small-scale aggregation, an enhanced YOLOX-S target detection algorithm for kiwifruit picking robots is proposed in this study. This involved designing a new multi-scale feature integration structure in which, with the aim of providing a small and lightweight model, the feature maps used for detecting large targets in the YOLOX model are eliminated, the feature map of small targets is sampled through the nearest neighbor values, the superficial features are spliced with the final features, the gradient of the SiLU activation function is perturbed, and the loss function at the output is optimized. The experimental results show that, compared with the original YOLOX-S, the enhanced model improved the detection average precision (AP) of kiwifruit images by 6.52%, reduced the number of model parameters by 44.8%, and improved the model detection speed by 63.9%. Hence, with its outstanding effectiveness and relatively light weight, the proposed model is capable of effectively providing data support for the 3D positioning and automated picking of kiwifruit. It may also successfully provide solutions in similar fields related to small target detection

Lightweight Detection Algorithm of Kiwifruit Based on Improved YOLOX-S

Considering the high requirements of current kiwifruit picking recognition systems for mobile devices, including the small number of available features for image targets and small-scale aggregation, an enhanced YOLOX-S target detection algorithm for kiwifruit picking robots is proposed in this study. This involved designing a new multi-scale feature integration structure in which, with the aim of providing a small and lightweight model, the feature maps used for detecting large targets in the YOLOX model are eliminated, the feature map of small targets is sampled through the nearest neighbor values, the superficial features are spliced with the final features, the gradient of the SiLU activation function is perturbed, and the loss function at the output is optimized. The experimental results show that, compared with the original YOLOX-S, the enhanced model improved the detection average precision (AP) of kiwifruit images by 6.52%, reduced the number of model parameters by 44.8%, and improved the model detection speed by 63.9%. Hence, with its outstanding effectiveness and relatively light weight, the proposed model is capable of effectively providing data support for the 3D positioning and automated picking of kiwifruit. It may also successfully provide solutions in similar fields related to small target detection

Two-Dimensional van der Waals Materials with Aligned In-Plane Polarization and Large Piezoelectric Effect for Self-Powered Piezoelectric Sensors

Piezoelectric two-dimensional (2D) van der Waals (vdWs) materials are highly desirable for applications in miniaturized and flexible/wearable devices. However, the reverse-polarization between adjacent layers in current 2D layered materials results in decreasing their in-plane piezoelectric coefficients with layer number, which limits their practical applications. Here, we report a class of 2D layered materials with an identical orientation of in-plane polarization. Their piezoelectric coefficients (e22) increase with layer number, thereby allowing for the fabrication of flexible piezotronic devices with large piezoelectric responsivity and excellent mechanical durability. The piezoelectric outputs can reach up to 0.363 V for a 7-layer α-In2Se3 device, with a current responsivity of 598.1 pA for 1% strain, which is 1 order of magnitude higher than the values of the reported 2D piezoelectrics. The self-powered piezoelectric sensors made of these newly developed 2D layered materials have been successfully used for real-time health monitoring, proving their suitability for the fabrication of flexible piezotronic devices due to their large piezoelectric responses and excellent mechanical durability

Repeated Exposure to Ozone Increases Alveolar Macrophage Recruitment into Asthmatic Airways

Rationale: Repeated, short-term exposures to ozone (O3) lead to attenuation of the acute lung function and airway inflammatory responses seen after a single exposure in healthy subjects, but it is unclear whether these acute responses also attenuate in subjects with asthma. Objective: To address this question by exposing 14 subjects with asthma to 0.2 ppm O3 for either 4 hours on a single day or 4 hours on 4 consecutive days (multiday [MD]). At least 3 weeks later, subjects underwent the alternate exposure. Methods: Spirometry was performed immediately pre- and postexposure and bronchoalveolar lavage (BAL) was obtained 18 hours after each exposure. Main Results: The decrease in FEV1 was greatest across Day 2 of the MD (MD2) exposure and then gradually declined on successive days of the MD exposure (mean ± SD decrease in FEV1 of 25.4 ± 18.0% across MD2 compared with 4.2 ± 6.5% across MD4). Respiratory symptoms followed a similar pattern to that of FEV1. Although the concentration of neutrophils in BAL after the MD4 exposure was not significantly different from that after the single-day exposure (1.7 ± 1.3 × 104 cells/ml vs. 1.2 ± 0.8 × 104 cells/ml, p = 0.20), the concentration of alveolar macrophages did significantly increase in BAL after the MD exposure (19.9 ± 9.7 × 104 cells/ml after MD4 vs. 12.1 ± 6.4 × 104 cells/ml after the single day). Conclusions: Alveolar macrophages are recruited to the airways of subjects with asthma with repeated short-term exposures to O3, suggesting a possible role for these cells in the chronic response to oxidant-induced injury

Intracranial aneurysms: links among inflammation, hemodynamics and vascular remodeling

Abnormal vascular remodeling mediated by inflammatory cells has been identified as a key pathologic component of various vascular diseases, including abdominal aortic aneurysms, brain arteriovenous malformations and atherosclerosis. Based on findings from observational studies that analysed human intracranial aneurysms and experimental studies that utilized animal models, an emerging concept suggests that a key component of the pathophysiology of intracranial aneurysms is sustained abnormal vascular remodeling coupled with inflammation. This concept may provide a new treatment strategy to utilize agents to inhibit inflammation or cytokines produced by inflammatory cells such as matrix metalloproteinases. Such an approach would aim to stabilize these vascular lesions and prevent future expansion or rupture