63 research outputs found
Wind Sensor
Wind measurement is needed in many practical and scientific research situations. Some specific applications require to precisely measuring both wind direction and wind speed at the same time. Current commercial sensors for wind direction and wind speed measurement usually use ultrasonic technology and the sensors are very expensive (\u3e $1500). In addition, the sensors are large in dimension and cannot measure airflow patterns in high spatial resolution. Therefore new and low cost wind speed and direction sensors that can satisfy the specific requirements are needed. This research project will develop a low cost and compact anemometer to measure the wind speed as well as three dimensional wind directions. Four prototypes are built and tested with a better improvement on each prototype. Data are collected by using LabVIEW and analyzed by using Matlab and Excel. The last prototype is tested successfully to verify the concepts that we would expect and qualitatively analyzed. Some improvements can be implemented to this wind sensor for commercial usage
Improving Ammonia Emission Modeling and Inventories by Data Mining and Intelligent Interpretation of the National Air Emission Monitoring Study Database
Ammonia emission is one of the greatest environmental concerns in sustainable agriculture development. Several limitations and fundamental problems associated with the current agricultural ammonia emission modeling and emission inventories have been identified. They were associated with a significant disconnection between field monitoring data and knowledge about the data. Comprehensive field measurement datasets have not been fully exploited for scientific research and emission regulations. This situation can be considerably improved if the currently available data are better interpreted and the new knowledge is applied to update ammonia emission modeling techniques. The world’s largest agricultural air quality monitoring database with more than 2.4 billion data points has recently been created by the United States’ National Air Emission Monitoring Study. New approaches of data mining and intelligent interpretation of the database are planned to uncover new knowledge and to answer a series of questions that have been raised. The expected results of this new research idea include enhanced fundamental understanding of ammonia emissions from animal agriculture and improved accuracy and scope in regional and national ammonia emission inventories
The Bcl-2/xL inhibitor ABT-263 increases the stability of Mcl-1 mRNA and protein in hepatocellular carcinoma cells
Background
Hepatocellular carcinoma (HCC) is one of the major causes of mortality. ABT-263 is a newly synthesized, orally available Bcl-2/xL inhibitor that shows promising efficacy in HCC therapy. ABT-263 inhibits the anti-apoptotic activity of Bcl-2 and Bcl-xL, but not Mcl-1. Previous reports have shown that ABT-263 upregulates Mcl-1 in various cancer cells, which contributes to ABT-263 resistance in cancer therapy. However, the associated mechanisms are not well known.
Methods
Western blot, RNAi and CCK-8 assays were used to investigate the relationship between Mcl-1 upregulation and ABT-263 sensitivity in HCC cells. Real-time PCR and Western blot were used to detect Mcl-1 mRNA and protein levels. Luciferase reporter assay and RNA synthesis inhibition assay were adopted to analyze the mechanism of Mcl-1 mRNA upregulation. Western blot and the inhibition assays for protein synthesis and proteasome were used to explore the mechanisms of ABT-263-enhanced Mcl-1 protein stability. Trypan blue exclusion assay and flow cytometry were used to examine cell death and apoptosis.
Results
ABT-263 upregulated Mcl-1 mRNA and protein levels in HCC cells, which contributes to ABT-263 resistance. ABT-263 increased the mRNA level of Mcl-1 in HCC cells by enhancing the mRNA stability without influencing its transcription. Furthermore, ABT-263 increased the protein stability of Mcl-1 through promoting ERK- and JNK-induced phosphorylation of Mcl-1Thr163 and increasing the Akt-mediated inactivation of GSK-3β. Additionally, the inhibitors of ERK, JNK or Akt sensitized ABT-263-induced apoptosis in HCC cells.
Conclusions
ABT-263 increases Mcl-1 stability at both mRNA and protein levels in HCC cells. Inhibition of ERK, JNK or Akt activity sensitizes ABT-263-induced apoptosis. This study may provide novel insights into the Bcl-2-targeted cancer therapeutics.This study was supported in part by Chongqing Natural Science Foundation (cstc2011BB5030 and 2013jjB10015), the National Natural Science Foundation of China (31201068, 81273226 and 81228005) and the Scientific Funds of Third Military Medical University (2011XHG02 and 2012XZH01)
The novel BH-3 mimetic apogossypolone induces Beclin-1- and ROS-mediated autophagy in human hepatocellular carcinoma cells
Apogossypolone (ApoG2), a novel derivative of gossypol, exhibits superior antitumor activity in Bcl-2 transgenic mice, and induces autophagy in several cancer cells. However, the detailed mechanisms are not well known. In the present study, we showed that ApoG2 induced autophagy through Beclin-1- and reactive oxygen species (ROS)-dependent manners in human hepatocellular carcinoma (HCC) cells. Incubating the HCC cell with ApoG2 abrogated the interaction of Beclin-1 and Bcl-2/xL, stimulated ROS generation, increased phosphorylation of ERK and JNK, and HMGB1 translocation from the nucleus to cytoplasm while suppressing mTOR. Moreover, inhibition of the ROS-mediated autophagy by antioxidant N-acetyl-cysteine (NAC) potentiates ApoG2-induced apoptosis and cell killing. Our results show that ApoG2 induced protective autophagy in HCC cells, partly due to ROS generation, suggesting that antioxidant may serve as a potential chemosensitizer to enhance cancer cell death through blocking ApoG2-stimulated autophagy. Our novel insights may facilitate the rational design of clinical trials for Bcl-2-targeted cancer therapy.Grant support: This study was supported in part by Chongqing Natural Science Foundation (CSTC, 2011BB5030), and by the Scientific Funds of Third Military Medical University (2011XHG02)
Quality Assured Measurements of Animal Building Emissions: Gas Concentrations
Comprehensive field studies were initiated in 2002 to measure emissions of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), methane (CH4), nonmethane hydrocarbons (NMHC), particulate matter \u3c10 µm in diameter, and total suspended particulate from swine and poultry production buildings in the United States.
This paper focuses on the quasicontinuous gas concentration measurement at multiple locations among paired barns in seven states. Documented principles, used in air pollution monitoring at industrial sources, were applied in developing quality assurance (QA) project plans for these studies. Air was sampled from multiple locations with each gas analyzed with one high quality commercial gas analyzer that was located in an environmentally controlled on-farm instrument shelter. A nominal 4 L/min gas sampling system was designed and constructed with Teflon wetted surfaces, bypass pumping, and sample line flow and pressure sensors. Three-way solenoids were used to automatically switch between multiple gas sampling lines with ≥10 min sampling intervals. Inside and outside gas sampling probes were between 10 and 115 m away from the analyzers. Analyzers used chemiluminescence, fluorescence,photoacoustic infrared, and photoionization detectors for NH3, H2S, CO2, CH4, and NMHC, respectively. Data were collected using personal computer-based data acquisition hardware and software. This paper discusses the methodology of gas concentration measurements and the unique challenges that livestock barns pose for achieving desired accuracy and precision, data representativeness, comparability and completeness, and instrument calibration and maintenance
Queuing Theory-Guided Performance Evaluation for a Reconfigurable High-Speed Device Interconnected Bus
The downregulation of ATG4B mediated by microRNA-34a/34c-5p suppresses rapamycin-induced autophagy
Objective(s): Autophagy-related 4B (ATG4B) plays an important role in the process of autophagy induction. However, the molecular events that govern the expression of ATG4B in this process are not well known. Materials and Methods: Human ATG4B 3'-UTR region (1377 nt) containing miR-34a/miR-34c-5p binding site was amplified by PCR. Luciferase assay was used to assess the activity of reporter genes. Real-time PCR was used to detect the levels of miR-34a and miR-34c-5p. Western blot was used to analyze the protein levels of ATG4B, LC3 and p62. Results: Both miR-34a and miR-34c-5p could directly target the 3'-UTR of ATG4B mRNA at same site. Overexpression of either miR-34a or miR-34c-5p significantly down-regulated ATG4B at both mRNA and protein levels and this effect can be reversed by ATG4B overexpression. Moreover, Rapamycin-induced autophagy is accompanied with the upregulation of ATG4B and the downregulation of miR-34a/miR-34c-5p. Ectopic expression of either miR-34a or miR-34c-5p markedly suppressed rapamycin-triggered autophagy. Conclusion: In the present study, we found that miR34/ATG4B signaling axis involves in rapamycin-triggered autophagy. This study may provide a new insight for understanding the mechanisms of ATG4B regulation and autophagy induction
- …