[Pollution Characteristics and Source Apportionment of Atmospheric VOCs During Ozone Pollution Period in the Main Urban Area of Chongqing].

In late August 2020, a period of O3 pollution occurred in the main urban area of Chongqing and lasted for approximately 2 weeks (till early September). Ambient air samples, collected using Summa Canisters and DNPH sampling columns at three observation sites in the main urban area, were used to study the composition, photochemical reaction activity, and source apportionment of volatile organic compounds (VOCs) during the period of O3 pollution. The results showed that the mean volume fraction of TVOCs in the main urban area of Chongqing during the observation period was 45.08×10-9, and the components were ranked by volume fraction in the following order:OVOCs, alkanes, halohydrocarbons, alkenes, aromatics, and alkynes. Formaldehyde, ethylene, and acetone made up the higher volume fraction of VOCs, together accounting for more than 30% of TVOCs. OVOCs and alkenes contributed more to · OH loss rate (Li·OH) and ozone formation potential (OFP) and were the key VOCs components for ozone generation. The main active species in the OVOCs component were formaldehyde, acetaldehyde, and acrolein; the main active species in the alkene component were isoprene, ethylene, and n-butene. The ratio of xylene to ethylbenzene in VOCs was low, and they showed a significant correlation, indicating that the VOCs air mass in the main urban area was highly aging and affected by long-distance transmission from other areas. The source apportionment results of the PMF model showed five main sources of VOCs, namely secondary generation (27.67%), vehicle exhaust (26.56%), industrial emission (17.86%), plant (14.51%), and fossil fuel combustion (13.4%).

Astaxanthin inhibits homocysteine­induced endothelial cell dysfunction via the regulation of the reactive oxygen species­dependent VEGF­VEGFR2­FAK signaling pathway.

Increased plasma levels of homocysteine (Hcy) can cause severe damage to vascular endothelial cells. Hcy­induced endothelial cell dysfunction contributes to the occurrence and development of human cerebrovascular diseases (CVDs). Our previous studies have revealed that astaxanthin (ATX) exhibits novel cardioprotective activity against Hcy­induced cardiotoxicity in vitro and in vivo. However, the protective effect and mechanism of ATX against Hcy­induced endothelial cell dysfunction requires further investigation. In the present study, treatment of human umbilical vascular endothelial cells (HUVECs) with Hcy inhibited the migration, invasive and tube formation potentials of these cells in a dose­dependent manner. Hcy treatment further induced a time­dependent increase in the production of reactive oxygen species (ROS), and downregulated the expression of vascular endothelial growth factor (VEGF), phosphorylated (p)­Tyr­VEGF receptor 2 (VEGFR2) and p­Tyr397­focal adhesion kinase (FAK). On the contrary, ATX pre­treatment significantly inhibited Hcy­induced cytotoxicity and increased HUVEC migration, invasion and tube formation following Hcy treatment. The mechanism of action may involve the effective inhibition of Hcy­induced ROS generation and the recovery of FAK phosphorylation. Collectively, our findings suggested that ATX could inhibit Hcy­induced endothelial dysfunction by suppressing Hcy­induced activation of the VEGF­VEGFR2­FAK signaling axis, which indicates the novel therapeutic potential of ATX in treating Hcy­mediated CVD.

[Systematic review of effectiveness and safety of pudilan Xiaoyan oral liquid in treating pediatric suppurative tonsilitis].

The review aims to assess the effectiveness and safety Pudilan Xiaoyan oral liquid in treating pediatric suppurative tonsillitis systematically through searching relevant electronic database and collecting relevant literature. Meta-analysis was performed with the RevMan 5.3 software. Eighteen RCTs of 1 883 patients of pediatric suppurative tonsillitis were included. Meta-analysis showed that： compared with the application of antibiotics alone, combined with Pudilan can effectively improve the treatment of pediatric suppurative tonsillitis in efficacy rate and shorten the time of recovering normal temperature, the time of tonsil purulent discharge and can also reduce the extinction time of sore throat, antiadoncus or congestion subsided and appetite recovery. There was no severe adverse reaction during the treatment. Compared with the application of antibiotics alone, combined with Pudilan may be more effective and safe in the treatment of pediatric suppurative tonsillitis, which can not be strongly proved at present for lack of studies with high quality.

[Characteristics of atmospheric visibility change and its influence factors in Hefei City, Anhui, China.] / åˆè‚¥å¸‚å¤§æ°”èƒ½è§åº¦å˜åŒ–ç‰¹å¾åŠå ¶å½±å“å› ç´ .

Using the observation data of Hefei atmospheric visibility and meteorological elements and PM2.5 and PM10 concentrations at same period from October 2013 to June 2015, based on comprehensive analysis of the impact factors on atmospheric visibility, the relationships among the relative humidity (RH), PM2.5 and PM10 concentrations and visibility were explored. The results showed that the correlation between RH and Hefei atmospheric visibility was most significant during the period of study. When RH<60%, the coefficients of correlation between PM2.5, PM10 concentrations and atmospheric visibility increased gradually with the increasing RH. When RH>60%, the coefficients of correlation between the particles concentration in atmosphere and atmospheric visibility showed a decreasing trend. When 50%≤RH<60%, the coefficients of correlation between PM2.5, PM10 concentrations and atmosphere visibility were higher. When RH was relatively higher, the atmospheric visibility was mainly affected by the relative humidity, on the contrary, the concentration of particles had a greater influence on the visibility. When RH>70%, the change amplitude of contour line of atmospheric visibility was larger, and the impacts of RH on atmospheric visibility were intensified. According to the formula fitted by the data of RH, PM2.5, PM10 concentrations and atmospheric visibility, the nonlinear fitting model was better than multivariate linear fitting model in simulating the change of atmospheric visibility.

Experimental study of the protective effects of SYVN1 against diabetic retinopathy.

Genetic factors play an important role in the pathogenesis of diabetic retinopathy (DR). While many studies have focused on genes that increase susceptibility to DR, herein, we aimed to explore genes that confer DR resistance. Previously, we identified Hmg CoA reductase degradation protein 1 (SYVN1) as a putative DR protective gene via gene expression analysis. Transgenic mice overexpressing SYVN1 and wild-type (WT) mice with streptozotocin-induced diabetes were used in this experiment. Retinal damage and vascular leakage were investigated 6 months after induction of diabetes by histopathological and retinal cell apoptosis analyses and by retinal perfusion of fluorescein isothiocyanate-conjugated dextran. Compared with diabetic WT mice, diabetic SYVN1 mice had significantly more cells and reduced apoptosis in the retinal ganglion layer. Retinal vascular leakage was significantly lower in diabetic SYVN1 mice than in diabetic WT mice. The expression levels of endoplasmic reticulum (ER) stress-related, pro-inflammatory, and pro-angiogenic genes were also analyzed. Lower expression levels were observed in diabetic SYVN1 mice than in WT controls, suggesting that SYVN1 may play an important role in inhibiting ER stress, chronic inflammation, and vascular overgrowth associated with DR. Thus, these results strongly supported our hypothesis that SYVN1 confers DR resistance.