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Multi-layer circuit board has the problem of poor heat dissipation performance, which limits its application in high frequency circuit. In this experiment, polytetrafluoroethylene (PTFE)/SiO2 high thermal conductivity composite film materials were prepared with Al2O3 as filler to enhance the thermal conductivity of multi-layer circuit boards. PTFE/SiO2 composite films were prepared by impregnation process combined with high temperature sintering by adding different amounts of Al2O3 into PTFE. The effects of Al2O3 content on the microstructure, density, thermal conductivity and mechanical properties of PTFE/SiO2 composite films were studied. The results show that with the increase of Al2O3 content, the thermal conductivity of the composite film shows an upward trend, and the density and mechanical strength show a trend of increasing first and then decreasing. When the Al2O3 content is 4%, the PTFE/SiO2 composite film (sample 3) has the least micro-defects, the highest density and mechanical strength, and has a reasonable thermal conductivity and electrical insulation. The density of sample 3 is 2.119 g/cm³, the mechanical strength is 17.3 MPa, the thermal conductivity is 0.98 W/(m·K), and the volume resistivity is 380.9 GΩ·m. [ABSTRACT FROM AUTHOR]

Corticotropin-releasing factor (CRF), the stress-related neuropeptide, acts as a neurotransmitter in the brain norepinephrine nucleus, locus coeruleus (LC), to activate this system during stress. CRF shifts the mode of LC discharge from a phasic to a high tonic state that is thought to promote behavioral flexibility. To investigate this, the effects of CRF administered either intracerebroventricularly (30-300 ng, i.c.v.) or directly into the LC (intra-LC; 2-20 ng) were examined in a rat model of attentional set shifting. CRF differentially affected components of the task depending on dose and route of administration. Intracerebroventricular CRF impaired intradimensional set shifting, reversal learning, and extradimensional set shifting (EDS) at different doses. In contrast, intra-LC CRF did not impair any aspect of the task. The highest dose of CRF (20 ng) facilitated reversal learning and the lowest dose (2 ng) improved EDS. The dose-response relationship for CRF on EDS performance resembled an inverted U-shaped curve with the highest dose having no effect. Intra-LC CRF also elicited c-fos expression in prefrontal cortical neurons with an inverted U-shaped dose-response relationship. The number of c-fos profiles was positively correlated with EDS performance. Given that CRF excites LC neurons, the ability of intra-LC CRF to activate prefrontal cortical neurons and facilitate EDS is consistent with findings implicating LC-norepinephrine projections to medial prefrontal cortex in this process. Importantly, the results suggest that CRF release in the LC during stress facilitates shifting of attention between diverse stimuli in a dynamic environment so that the organism can adapt an optimal strategy for coping with the challenge. [ABSTRACT FROM AUTHOR]

Cities are the center of energy consumption. Electrification integrates urban energy structure and achieves the efficient use of clean energy. Exploring the urban impact of accelerated electrification under the low-carbon path is crucial to reducing urban pollution and carbon. Based on the Long-range Energy Alternative Planning System(LEAP-DG), this study set up three scenarios, including the baseline, low-carbon, and accelerated electrification scenarios, to evaluate the emission reduction potential of electrification under different power structures, quantify the contribution of key sectors, and discuss the coordinated emission reduction effect of Dongguan, a typical manufacturing city in Guangdong. The results showed that accelerated electrification under the low-carbon path would reduce the emission intensity of power pollutants, and in 2050, Dongguan will further reduce CO 2 , NO x , VOC, and CO by 7.35×10 6 , 1.28×10 4 , 1.62×10 4 , and 8.13×10 4 t; SO 2 and PM 2.5 emission reductions on the consumption side and increased emissions on the production side had been balanced. Accelerated electrification in the industrial and transportation sectors would reduce CO 2 and air pollutant emissions at the same time, and the transportation sector would benefit from the high conversion efficiency of fuel vehicles and electric vehicles, reducing CO 2 , CO, VOC, and NO x by 5.42×10 6 , 7.76×10 4 , 1.43×10 4 , and 1.06×10 4 t, respectively, in 2050. In the building sector with high electrification rates, coal power was higher in extra electricity, increasing CO 2 and pollutant emissions. Under the optimization of power supply structure, cities can reasonably adjust the electrification of different departments to achieve targeted pollution prevention and control.

With the rapid development of urbanization, ozone (O 3 ) pollution is an ongoing occurrence in the Pearl River Delta (PRD) region in China. The effective control of O 3 pollution is a great challenge owing to the nonlinear relationship between O 3 and precursor emissions and the effect of meteorological conditions. Based on the regional air quality model CAMx-OSAT (ozone source apportionment technology), O 3 formation regimes were determined, and inter-city transportation across PRD was quantified under different transmission channels. The results showed that spatial differences were observed for the O 3 formation regimes under different transmission channels. The VOCs-sensitive regime was mainly located in the central areas of the PRD region, and the NO x -sensitive regime was distributed in the suburban areas of the PRD regions under calm wind conditions. When the northeast wind was prevailing, the polluted air mass of the urban agglomeration was transmitted southwesterly downward, resulting in the downwind areas being transformed to VOCs-sensitive; the upwind areas were still NO x -sensitive. Under the southeast wind, the VOCs-sensitive regime had a banding distribution along the southeast-northwest direction, and the remaining areas were NO x -sensitive. With the influence of transmission channels, downwind cities were significantly affected by the transmission of upwind urban agglomerations (41%-87%), whereas the local formation was the main contributor under the calm wind conditions (60%-87%). To explore the relationship between O 3 and precursor emissions, a series of sensitivity tests were designed. The results showed that maximized areas (20%-36%) with reductions in O 3 can be achieved by reducing VOCs and NO x in the corresponding sensitive regimes, and the maximized level with the reduction in O 3 can be fulfilled by reducing VOCs in the VOCs-sensitive regime. For the typical city Jiangmen, the area that met the standard increased the most under the calm wind (11%) and southeast wind (8%) conditions when VOCs and NO x were reduced in the corresponding sensitive regimes. Additionally, under northeast wind conditions, reducing VOCs in the VOCs-sensitive regime can more effectively control O 3 , as the area up to the standard increased by 140%.

Based on the atmospheric pollutant data from twelve monitoring sites in the Guangdong-Hong Kong-Macao Pearl River Delta Regional Air Quality Monitoring Network, the mass concentration trends of atmospheric photochemical oxidants (O x , NO 2 +O 3 ) and PM 2.5 during 2013-2017 were studied. The complex nonattainment pollution of O x and PM 2.5 is defined as the daily average mass concentration of NO 2 and PM 2.5 and daily maximum 8 h average (O 3 MDA8) mass concentration of O 3 simultaneously that exceeds the Chinese grade Ⅱ national air quality standard. The characteristics and meteorological factors that influence the complex nonattainment pollution of O x and PM 2.5 at different types of areas were analyzed. The results indicate that from 2013 to 2017, the annual average mass concentration of PM 2.5 in the Pearl River Delta (PRD) region decreased from (44±7) μg·m -3 to (32±4) μg·m -3 , which met the annual standard for three consecutive years. The annual average mass concentration of O x decreased from (127±14) μg·m -3 in 2013 to (114±12) μg·m -3 in 2016 and then showed a general rebound trend to (129±13) μg·m -3 in 2017 when O 3 concentrations increased significantly (10 μg·m -3 ). The proportion of pollution processes with O 3 as the primary pollutant increased from 33% in 2013 to 78% in 2017, and the regional characteristics of simultaneous pollution in multiple cities have been highlighted. The complex nonattainment pollution of O x and PM 2.5 occurred 60 times during the study period, primarily in urban sites (78%) and suburban sites (22%). The largest number of days of complex nonattainment pollution occurred in autumn (52%) because of strong solar radiation that was conducive to ozone formation, and consequently, the high oxidization of the atmosphere promoted the secondary generation of PM 2.5 . The weather conditions that caused the complex nonattainment pollution in the PRD mainly include outflow-high-pressures (43%), subtropical-high-pressures(30%), and tropical-depressions (27%). In terms of specific meteorological conditions, when the temperature was in the range of 20-25℃ and relative humidity was in the range of 60%-75%, the proportion of complex nonattainment pollution was the highest (22%). When O 3 pollution was substantial, the high relative humidity and low wind speed during the nighttime caused the concentration of NO 2 and PM 2.5 to rise significantly, and then the high temperatures during the day aggravated the complex nonattainment pollution.

We aimed to obtain the most comprehensive picture to date of the prognostic value of caveolin-1 (Cav-1) in genitourinary carcinoma by meta-analyzing all eligible studies in PubMed and EMBASE. Data on patient clinical characteristics, cancer-specific survival (CSS) and recurrence-free survival (RFS) were extracted. The meta-analysis included 6 articles on prostate cancer, 5 on renal cancer, 1 on bladder cancer and 1 on transition cell carcinoma of the upper urinary tract. Two studies examining the association of ELISA-measured Cav-1 levels in serum with RFS in 621 patients with prostate cancer gave a combined hazard ratio (HR) of 1.25 (95% CI 0.36 to 4.36). The other 4 studies on prostate cancer examined the association of immunohistochemically determined Cav-1 levels in cancerous tissue with RFS and gave a combined HR of 1.83 (95% CI 1.36 to 2.47). Three studies on renal cancer examining the association of Cav-1 levels with CSS gave a multivariate HR of 1.98 (95% CI 1.35 to 2.90). The single studies on bladder carcinoma and upper urinary tract carcinoma gave, respectively, a multivariate HR of 2.28 (95% CI 1.09 to 4.74) for the relationship of Cav-1 levels to DFS, and a multivariate HR of 5.08 (95% CI 1.799 to 14.342) for the relationship of Cav-1 levels to CSS. This meta-analysis of available evidence suggests that elevated Cav-1 levels in serum can predict poor survival in patients with genitourinary cancer, which may help identify high-risk patients earlier and guide clinical decision-making.

Objective: To determine risk factors associated with the prevalence of chronic obstructive pulmonary disease (COPD) in urban and rural populations in Chengdu., Methods: A multistage random cluster sampling method was adopted to select participants from four communities in Chengdu. All residents aged 40-70 yr. were eligible to participate in this study, which involved a questionnaire survey, physical examination and portable spirometry. Those with airflow limitations were also given post-bronchodilator testing 15 min after inhalation of a dose of 200 microg salbutamol. We defined a forced expiratory volume in one second/forced vital capacity (FEV1/FVC) of less than 70% as COPD. Logistic regression models were performed to identify risk factors of COPD., Results: Of a total of 1931 eligible participants, 1579 (81.77%) completed the questionnaire and spirometry. About 8.35% were identified with COPD: 7.69% in urban vs. 12.37% in rural (P<0.05). The prevalence of COPD increased with age (P<0.05) in the male and total populations. Rural COPD patients had a higher level of smoking rate and use of coal as fuel for cooking than their urban counterparts (P<0.05). But rural COPD patients had a lower level of BMI, waist circumference, literacy, and average household income per capita than their urban counterparts (P<0.05). The multivariate analysis showed that tobacco smoking index (pack-year), education, age and BMI were predictors of COPD for male patients; whereas, coal fuel usage, income and BMI were predictors of COPD for female patients., Conclusion: COPD prevalence is higher in rural areas than in urban Chengdu. Major risk factors of COPD include smoking, coal fuels and BMI.

Objective: To investigate the serum lipid levels in rural residents with diabetes and pre-diabetes conditions in Chengdu., Methods: Random cluster sampling method was employed to select participants of 35-70 year-old rural residents in Chengdu. The participants (n=971) were given standard 75 g oral glucose tolerance tests (OGTT) and divided into five groups: impaired fasting glucose (IFG) group, impaired glucose tolerance (IGT) group, IFG and IGT (IFG+ IGT) group, diabetes mellitus (DM) group and normal glucose tolerance (NGT) group. Their serum total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-c) and low density lipoprotein cholesterol (LDL-c) were measured., Results: The age-adjusted standardized prevalence of DM and pre-diabetes in rural residents in Chengdu were 12.8% and 34.5%, respectively, without significant gender differences. IGT was the most common type of abnormal glucose metabolism in pre-diabetes. High serum TG and LDL-c and low serum HDL-c were found in 45.9%, 30.6% and 9.9% participants with DM, respectively. High serum LDL-c and TG and low serum HDL-c were found in 38.1%, 30.6% and 7.6% of participants with IGR. Participants with DM or/and IGR had higher levels of LDL-c and TG and lower levels of HDL-c than those in the NGT group., Conclusion: Pre-diabetes and diabetes are prevalent in rural residents in Chengdu, which are usually accompanied with various degrees of dyslipidemia.

Objective: To explore the neurobiological basis involved in the pathogenesis of the lasting emotionality and cognitive impairment following severe psychological stress., Methods: Ninety-six male Wistar rats were divided randomly into 2 equal groups: group of predator stress (Group PS) put into a cage in the experimental box singly to be exposed to a cat in the box but outside the cage for 23-57 min until tremor, polypnea, and nares flaring appeared for 6 min so as to establish predator stress models, and control group, put into the cage without non-injurious exposure of cat. 1, 12, and 24 hours later 8 rats from each group were killed with the hippocampus taken out. Western blotting was used to detect the protein expressions of cAMP response element-binding protein (CREB), phosphorylated CREB (pCREB) and CREB binding protein (CBP). Twelve hours after the experiment 24 rats from each group were killed with their brains taken out to obtain serial coronary sections. Immunohistochemistry was used to detect the positive immunoreactivities of CREB, pCREB, and CBP., Results: Immunohistochemistry revealed that the absorbance (A) value of CREB-in the tissues of hippocampus and frontal cortex 12h after the cat exposure of Group PS were 0.55 +/- 0.13 and 0.88 +/- 0.20 respectively, both significantly lower than those of the control group (1.78 +/- 0.40 and 1.18 +/- 0.26 respectively, both P < 0.01), the A values of. pCREB in the hippocampus and frontal cortex of Group PS were 1.51 +/- 0.34 and 1.07 +/- 0.24 respectively, both significantly higher than those of the control group (0.47 +/- 0.11 and 0.48 +/- 0.11 respectively, both P < 0.01), and the A values of CBP in the hippocampus and frontal cortex of Group PS were 1.01 +/- 0.23 and 0.81 +/- 0.18 respectively, both significantly higher than those of the control group (0.52 +/- 0.12 and 0.29 +/- 0.07 respectively, both P < 0.01). Western blotting showed that the CREB protein expression levels 1 h and 24 h after the cat exposure of Group PS were 2.82 +/- 0.65 and 5.12 +/- 1.13 respectively, both significantly lower than those of the control group (11.86 +/- 2.47 and 10.56 +/- 2.38 respectively, both P < 0.01), the CBP protein expression levels 1 h and 24 h after the cat exposure of Group PS were 1.77 +/- 0.39 and 2.44 +/- 0.55 respectively, both significantly higher than those of the control group (1.06 +/- 0.24 and 0.86 +/- 0.20 respectively, both P < 0.01), and the pCREB protein expression levels 1 h and 12 h after the cat exposure of Group PS were 2.56 +/- 0.59 and 1.93 +/- 0.41 respectively, both significantly higher than those of the control group (1.04 +/- 0.22 and 0.96 +/- 0.21 respectively, both P < 0.01)., Conclusion: The dysfunction of CREB signaling in the central nervous system, especially in the hippocampal formation after predation stress may play an important role in the long-term neuropsychological sequelae following severe stress.