Estrogen Modulates the Sensitivity of Lung Vagal C Fibers in Female Rats Exposed to Intermittent Hypoxia

Obstructive sleep apnea is mainly characterized by intermittent hypoxia (IH), which is associated with hyperreactive airway diseases and lung inflammation. Sensitization of lung vagal C fibers (LVCFs) induced by inflammatory mediators may play a central role in the pathogenesis of airway hypersensitivity. In females, estrogen interferes with inflammatory signaling pathways that may modulate airway hyperreactivity. In this study, we investigated the effects of IH on the reflex and afferent responses of LVCFs to chemical stimulants and lung inflammation in adult female rats, as well as the role of estrogen in these responses. Intact and ovariectomized (OVX) female rats were exposed to room air (RA) or IH for 14 consecutive days. On day 15, IH enhanced apneic responses to right atrial injection of chemical stimulants of LVCFs (e.g., capsaicin, phenylbiguanide, and α,β-methylene-ATP) in intact anesthetized females. Rats subjected to OVX prior to IH exposure exhibited an augmented apneic response to the same dose of stimulants compared with rats subjected to other treatments. Apneic responses to the stimulants were completely abrogated by bilateral vagotomy or perivagal capsaicin treatment, which blocked the neural conduction of LVCFs. Electrophysiological experiments revealed that in IH-exposed rats, OVX potentiated the excitability of LVCFs to stimulants. Moreover, LVCF hypersensitivity in rats subjected to OVX prior to IH exposure was accompanied by enhanced lung inflammation, which was reflected by elevated inflammatory cell infiltration in bronchoalveolar lavage fluid, lung lipid peroxidation, and protein expression of inflammatory cytokines. Supplementation with 17β-estradiol (E2) at a low concentration (30 μg/ml) but not at high concentrations (50 and 150 μg/ml) prevented the augmenting effects of OVX on LVCF sensitivity and lung inflammation caused by IH. These results suggest that ovarian hormones prevent the enhancement of LVCF sensitivity and lung inflammation by IH in female rats, which are related to the effect of low-dose estrogen

The Ninth Visual Object Tracking VOT2021 Challenge Results

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Effects of organic acids on through-hole fillingby copper electroplating

Through-hole (TH) filling of a printed circuit board (PCB) by copper electroplating was performed usingformic acid, acetic acid and propionic acid instead of H2SO4. Tetranitroblue tetrazolium chloride (TNBT)was used as an inhibitor to perform a fast copper protruding deposition at the hole center during plating.The use of an organic acid instead of H2SO4overcomes two issues caused by H2SO4: poor copper fillingperformance at high H2SO4concentrations and a chap-like copper structure in the filled TH at low H2SO4concentrations. The filling performance using an organic acid was evaluated through the experimentalexamination of cross-sections of THs. The inhibition mechanism of TNBT on copper deposition was char-acterized by galvanostatic measurements with real-time injection of various acids, cyclic voltammetry(CV), linear sweep voltammetry (LSV) and UV–vis spectrophotometry. The results show that TNBT is elec-trochemically reducible only in the presence of protons. Its inhibiting strength and mechanism dependon the pH value, the chloride ion concentration and the cathodic potential. An electrochemical reactionmechanism was proposed herein to explain the filling plating behaviors and results