166 research outputs found
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CO2 per se activates carbon dioxide receptors.
Carbon dioxide has been used in traps for more than six decades to monitor mosquito populations and help make informed vector management decisions. CO2 is sensed by gustatory receptors (GRs) housed in neurons in the maxillary palps. CO2-sensitive GRs have been identified from the vinegar fly and mosquitoes, but it remains to be resolved whether these receptors respond to CO2 or bicarbonate. As opposed to the vinegar fly, mosquitoes have three GR subunits, but it is assumed that subunits GR1 and GR3 form functional receptors. In our attempt to identify the chemical species that bind these receptors, we discovered that GR2 and GR3 are essential for receptor function and that GR1 appears to function as a modulator. While Xenopus oocytes coexpressing Culex quinquefasciatus subunits CquiGR1/3 and CquiGR1/2 were not activated, CquiGR2/3 gave robust responses to sodium bicarbonate. Interestingly, CquiGR1/2/3-coexpressing oocytes gave significantly lower responses. That the ternary combination is markedly less sensitive than the GR2/GR3 combination was also observed with orthologs from the yellow fever and the malaria mosquito. By comparing responses of CquiGR2/CquiGR3-coexpressing oocytes to sodium bicarbonate samples (with or without acidification) and measuring the concentration of aqueous CO2, we showed that there is a direct correlation between dissolved CO2 and receptor response. We then concluded that subunits GR2 and GR3 are essential for these carbon dioxide-sensitive receptors and that they are activated by CO2 per se, not bicarbonate
Protective effect of GLP-1 analog liraglutide on podocytes in mice with diabetic nephropathy
Protection of podocytes is one of the important means to delay the progression of diabetic nephropathy (DN), and glucagon-like peptide-1 (GLP-1) has been shown to have a protective effect on the kidney in DN models, but whether it h as a protective effect on podocytes and the potential mechanisms of action remain largely unknown. In the present study, we established a type 2 diabetes mellitus (T2DM) mouse model by high-fat diet feeding combined with streptozotocin (STZ) induction and admini stered the intervention for 14 weeks. We found that liraglutide significantly ameliorate d podocyte injury in DN mice. Mechanistically, we detected glucagon-like peptide-1 receptor (GLP-1R) protein expression levels in kidney tissues by immunohistochemical stai ning, immunofluorescence staining, and western blotting and found that podocytes could express GLP-1R and liraglutide treatment could restore GLP-1R expression in the kidney tissues of DN mice. Furthermore, we found that NLRP3-induced inflammation and pyropt osis were positively correlated with podocyte injury in DN mice, and liraglutide inh ibited the expression of NLRP3-induced inflammation and pyroptosis-related proteins. Our results suggest that liraglutide protects DN mouse podocytes by regulating GLP-1R in renal tissues and by regulating NLRP3-induced inflammation and pyroptosis
āYou Should Have Seen the Look on Your Faceā¦ā: Self-awareness of Facial Expressions
The awareness of facial expressions allows one to better understand, predict, and regulate his/her states to adapt to different social situations. The present research investigated individualsā awareness of their own facial expressions and the influence of the duration and intensity of expressions in two self-reference modalities, a real-time condition and a video-review condition. The participants were instructed to respond as soon as they became aware of any facial movements. The results revealed that awareness rates were 57.79% in the real-time condition and 75.92% in the video-review condition. The awareness rate was influenced by the intensity and (or) the duration. The intensity thresholds for individuals to become aware of their own facial expressions were calculated using logistic regression models. The results of Generalized Estimating Equations (GEE) revealed that video-review awareness was a significant predictor of real-time awareness. These findings extend understandings of human facial expression self-awareness in two modalities
Research on Turning Motion Targets and Velocity Estimation in High Resolution Spaceborne SAR
The development of high resolution SAR makes the influence of moving target more prominent, which results in defocusing and other unexplained phenomena. This paper focuses on the research of imaging signatures and velocity estimation of turning motion targets. In this paper, the turning motion is regarded as the straight line motion of continuous change of moving direction. Through the analysis of the straight line motion with constant velocity and the geometric modeling of the turning motion in spaceborne SAR, the imaging signatures of the turning motion target are obtained, such as the broken line phenomenon at the curve. Furthermore, a method for estimating the turning velocity is proposed here. The radial velocity is calculated by the azimuth offset of the turning motion target and the azimuth velocity is calculated by the phase error compensated in the refocusing process. The amplitude and direction of the velocity can be obtained by using both of them. The results of simulation and GF-3 data prove the accuracy of the analysis of turning motion imaging signatures, and they also show the accuracy and validity of the velocity estimation method in this paper
Focusing and Parameter Estimation of Fluctuating Targets in High Resolution Spaceborne SAR
Complex motion can cause serious defocusing phenomena in high resolution spaceborne SAR cases, which then lead to decreased image resolution. In this study, we built a simulation model to quantitatively analyze the signature and effect on maritime fluctuating targets in high resolution cases. To deal with formed Single-Look Complex (SLC) SAR images containing fluctuating targets, we implement a motion-compensation and fine-focusing method to obtain refocused images and the fluctuation parameters. We demonstrate the effectiveness and correctness of the proposed approach in focusing and estimating the parameters of fluctuating targets by processing the simulation results and archived images acquired by Terra-SAR in hybrid spotlight mode
An Improved BAQ Encoding and Decoding Method for Improving the Quantized SNR of SAR Raw Data
When the original echo data of SAR are saturated for quantization, the performance of the commonly used block adaptive quantization (BAQ) algorithm will be degraded, which will degrade the imaging quality. This article proposes an improved Llody-Max codec method, which only needs to change the codec look-up table to get better quantization performance when the original echo is saturated. The simulation results show that the proposed method can reduce the quantization power loss, improve the echo signal-to-noise ratio (SNR), and reduce the influence of quantization saturation on the scattering mechanism of polarized SAR data, which have good practical application value
A method to alleviate false-positive results of the Elecsys HIV combi PT assay
Abstract To explore the effects of urea dissociation on reducing false-positive results of Ā theĀ Elecsys HIV combi PT assay. A retrospective analysis was used to evaluate the false-positive rate of the Elecsys HIV combi PT assay. Six false-positive sera, six positive sera and six sera from patients with early HIV infection were collected. Dissociation was performed using 1Ā mol/L, 2Ā mol/L, 4Ā mol/L, 6Ā mol/L, or 8Ā mol/L urea, and HIV screening assay were then detected to select the appropriate concentration of urea dissociation. Next, 55 false-positive sera and 15 sera from early HIV infection were used to verify the best concentration of urea to achieve dissociation. Retrospective analysis showed that the COI of the Elecsys HIV combi PT assay in false-positive sera ranged from 1.0 to 200.0, and approximately 97.01%(227/234) of false-positive sera were in the range of 1.0ā15.0. The avidity index (AI) in positive and false-positive sera decreased as the urea dissociation concentration increased. When the dissociation concentration was 6Ā mol/L, the AI of false-positive serum was between 0.0234 and 0.2567, and the AI of early HIV infection sera was between 0.4325 and 0.5017. The difference in AI between false-positive and positive samples was significant. When negativity was defined as an AI of less than 0.3970, the sensitivity and specificity were 100.0% and 100.0%, respectively. Urea-mediated dissociation could significantly reduce the false-positive rate of the Elecsys HIV combi PT assay with a low COI. Our findings provided a reference for distinguishing positive and false-positive of the Elecsys HIV combi PT assay
To bind or not to bind? Different temporal binding effects from voluntary pressing and releasing actions.
Binding effect refers to the perceptual attraction between an action and an outcome leading to a subjective compression of time. Most studies investigating binding effects exclusively employ the "pressing" action without exploring other types of actions. The present study addresses this issue by introducing another action, releasing action or the voluntary lifting of the finger/wrist, to investigate the differences between voluntary pressing and releasing actions. Results reveal that releasing actions led to robust yet short-lived temporal binding effects, whereas pressing condition had steady temporal binding effects up to super-seconds. The two actions also differ in sensitivity to changes in temporal contiguity and contingency, which could be attributed to the difference in awareness of action. Extending upon current models of "willed action," our results provide insights from a temporal point of view and support the concept of a dual system consisting of predictive motor control and top-down mechanisms
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