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In order to improve the mechanical properties of carbon fiber reinforced concrete, the effect of polymer latex powder content on the properties of concrete under the four carbon fiber content (0, 0.1 %, 0.2 %, 0.3 %) was studied by adding VAE polymer latex powder. The compressive strength, flexural strength, compressive peak strain, flexural peak strain and compression ratio of concrete were analyzed. The test results show that with the increase of the amount of VAE polymer latex powder, the effect of latex powder on the performance of carbon fiber concrete increased first and then decreased. The performance of carbon fiber concrete was improved most obviously when the content of latex powder was within 4%-8%, and there was an interaction between carbon fiber content and latex powder content. [ABSTRACT FROM AUTHOR]

To study the effect of carbon nanofibers on the durability of concrete, the freeze-thaw cycle test, penetration test and carbonization test of carbon nanofiber reinforced concrete with carbon nanofibers with different volume (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) were carried out. In addition, the microscopic modification mechanism of carbon nanofibers to concrete durability was further investigated by SEM test. The results show that the carbon nanofibers could improve the micro-morphology of concrete through fiber bridging and pore filling, significantly improving the durability of concrete. When the content of carbon nanofibers was 0.3%, the frost resistance, impermeability and anti-carbonization performance of carbon nanofiber reinforced concrete were the best. When the number of freeze-thaw cycles was the same, as the amount of carbon nanofibers increased, the mass loss rate and compressive strength loss rate of concrete decreased first and then increased. The seepage height and relative permeability coefficient of concrete decreased first and then increased with the increase content of carbon nanofibers. Under the same carbonization age, the carbonation depth of concrete decreased first and then increased with the increase content of carbon nanofiber. Frost resistance, impermeability and anti-car bonization performance of carbon nanofiber reinforced concrete with 0.5% of carbon nanofibers were still better than that of plain concrete. [ABSTRACT FROM AUTHOR]

With the acceleration of industrialization and agriculture, soil heavy metal pollution has become increasingly serious. Copper, though an essential trace element for the growth and development of living organisms, is one of the main heavy metal pollutants. Excess copper in soil is toxic to plants and threatens human health via food chain. Bioremediation has received extensive attention as a novel technology for heavy-metal-contaminated soils. Here, we review the development of bioremediation technologies, including phytoremediation, microbial remediation, plant-microbe combined remediation, and animal remediation, for copper-contaminated soils, in order to provide a theoretical basis for the effective management of heavy-metal-contaminated soils and the sustainable development of agriculture.

Objective: To assess the differences between ultrasound cardiac output monitor (USCOM) and thermodilution (TD) systematically in cardiac function monitoring of critically ill patients., Methods: The Chinese and English literatures about the clinical trials which using USCOM and TD to monitor cardiac function published in CNKI, Wanfang database, China biomedical literature database, VIP database, China Clinical Trial Registration Center, PubMed, Embase and Cochrane Library were searched by computer from the establishment to December 2018. Some indicators, like cardiac output (CO), cardiac index (CI), stroke volume (SV) and other parameters were used to evaluate cardiac function. Literature search, quality evaluation and data extraction were conducted independently by two authors. The tailored Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used for literature quality evaluation. EndNote X6 was used for literature screening and management. RevMan 5.3 was used for Meta-analysis. Funnel chart analysis was used for publication bias., Results: A total of 26 studies involving 772 patients were included. Among them, there were 5 literatures found that the agreements of cardiac function between the USCOM and TD methods were poor. Meta-analysis showed that there was no significant difference between the two methods in CO and CI monitoring [CO: mean difference (MD) = -0.06, 95% confidence interval (95%CI) was -0.17 to 0.05, P = 0.31; CI: MD = -0.04, 95%CI was -0.13 to 0.05, P = 0.38]. Subgroup analysis of different TD methods [pulmonary artery catheter (PAC), pulse indicator continuous cardiac output (PiCCO)] and different windows of USCOM ultrasonic probe [aorta (AA), pulmonary artery (PA)] in CO monitoring was not shown significant difference yet (PAC: MD = -0.07, 95%CI was -0.18 to 0.04, P = 0.23; PiCCO: MD = 0.09, 95%CI was -0.31 to 0.50, P = 0.65; AA windows: MD = -0.14, 95%CI was -0.31 to 0.02, P = 0.09; PA windows: MD = -0.00, 95%CI was -0.15 to 0.14, P = 0.95; AA/PA windows: MD = 0.23, 95%CI was -0.40 to 0.86, P = 0.47). However, the difference in SV was statistically significant between the USCOM and TD method (MD = 1.48, 95%CI was 0.04 to 2.92, P = 0.04). Funnel chart showed that the literature distribution of CO and CI monitoring were basically symmetrical, indicating that the bias of literature publication is small., Conclusions: USCOM has good consistency with TD method in monitoring the cardiac function parameters of CO and CI, and different windows of ultrasonic probe of USCOM have no significant influence on the monitoring results, but there is significant difference in the consistency of the two methods in SV monitoring.