Study on the enhancement method of online monitoring image of dense fog environment with power lines in smart city.

In this research, an image defogging algorithm is proposed for the electricity transmission line monitoring system in the smart city. The electricity transmission line image is typically situated in the top part of the image which is rather thin in size. Because the electricity transmission line is situated outside, there is frequently a sizable amount of sky in the backdrop. Firstly, an optimized quadtree segmentation method for calculating global atmospheric light is proposed, which gives higher weight to the upper part of the image with the sky region. This prevents interference from bright objects on the ground and guarantees that the global atmospheric light is computed in the top section of the image with the sky region. Secondly, a method of transmission calculation based on dark pixels is introduced. Finally, a detail sharpening post-processing based on visibility level and air light level is introduced to enhance the detail level of electricity transmission lines in the defogging image. Experimental results indicate that the algorithm performs well in enhancing the image details, preventing image distortion and avoiding image oversaturation.

Nucleoside analogues alone or combined with vaccination prevent hepadnavirus viremia and induce protective immunity: alternative strategy for hepatitis B virus post-exposure prophylaxis.

OBJECTIVES: The current strategies for hepatitis B virus (HBV) post-exposure prophylaxis (PEP) are not generally available in remote and rural areas of developing countries and/or carry potential risks for infection with blood-borne transmitted pathogens. Nucleotide analogues (NAs) are successfully used for human immunodeficiency virus PEP, and maybe effective for HBV PEP. In this study, we tested the NA-based strategies for HBV PEP using the Chinese woodchuck model. METHODS: Chinese woodchucks were inoculated intravenously with different doses of woodchuck hepatitis virus (WHV). A deoxyguanosine analogue entacavir (ETV), a DNA vaccine pWHcIm, or ETV plus pWHcIm were applied to the infected animals 24h later. Twenty weeks later, the animals were re-challenged with WHV to test for the presence of immunity against WHV. RESULTS: Inoculation with different WHV doses had a strong influence on the course of WHV infection; NA alone or in combination with a DNA vaccine completely prevented viremia after a high dose of WHV inoculation in Chinese woodchucks and induced partial or complete protective immunity, respectively. CONCLUSIONS: NA-based PEP strategies (NA alone or in combination with vaccine) may be an alternative of HBV PEP, especially in those living in the remote and rural areas of the developing countries and the non-responders to the current vaccine, and may be valuable in the PEP of HBV and HIV co-infection after occupational and non-occupational exposure. Further clinical studies are warranted to confirm the valuable of NA-based strategies in HBV PEP.

Immunosuppressive drugs modulate the replication of hepatitis B virus (HBV) in a hydrodynamic injection mouse model.

Hepatitis B virus (HBV) reactivation and recurrence are common in patients under immunosuppression and can be controlled by hepatitis B immunoglobulin, antivirals, and hepatitis B vaccine. However, the detailed analysis of HBV infection under immunosuppression is essential for the prophylaxis and therapy for HBV reactivation and recurrence. In this study, HBV replication and T cell responses were analyzed in a HBV-transfected mouse model under immunosuppressive therapy. During the treatment, HBV replication was at a high level in mice treated with dexamethasone, cyclosporine, and cyclophosphamide, whereas was terminated in mice treated with mycophenolate mofetil. After the withdrawal, HBV replication was at low or high levels in the dexamethasone-treated mice or in both cyclosporine- and cyclophosphamide-treated mice. The early withdrawal of cyclosporine allowed the recovery of suppressed T cell responses and led to subsequent HBV clearance, while the adoptive immune transfer to the mice with HBV persistence led to HBV suppression. Taken together, long-term HBV persistence under immunosuppression depends on the immunosuppressive drugs used and on the treatment duration and is mediated by the suppressed intrahepatic CD8 T cell response. These data may be helpful for individualized immunosuppressive therapy in patients with high risk of HBV reactivation and recurrence, and the mouse system is suitable for studying HBV reactivation and recurrence under immunosuppression.

[Identification of the offspring of Vegfr2-luc transgenic mouse].

BACKGROUND AND OBJECTIVE: A transgenic mouse, Vegfr2-luc, in which a luciferase reporter (luc) is under control of the murine VEGFR2 promoter, can be used to track angiogenesis in vivo. The aim of this study is to identify the offspring of Vegfr2-luc transgenic mouse. METHODS: Luc was detected with PCR in genomic DNA of the new-born mouse. Luc expression in the offspring of Vegfr2-luc transgenic mouse was monitored with IVIS in vivo imaging system during post-natal development. Wound-healing models of Vegfr2-luc transgenic mouse offspring were established and the expression of luc was monitored during the wound-healing process. Luc activity and VEGFR2 mRNA expression in different organs were detected with luc Assay System and Real-time PCR respectively. RESULTS: PCR showed that 50% (56/112) of the offspring of Vegfr2-luc transgenic mouse carry luc. IVIS in vivo imaging results demonstrated that luc expression in Vegfr2-luc transgenic mouse dropped dramatically with age increase (P<0.001) and luc expression in the wound first increased and then decreased during the wound-healing process (P<0.001). Luc activity in female Vegfr2-luc transgenic mouse organs was positively correlated with VEGFR2 mRNA expression (r=0.948, P<0.001). Except testis, luc activity in male Vegfr2-luc transgenic mouse organs was also positively correlated with VEGFR2 mRNA expression (r=0.836, P<0.001). CONCLUSION: The offspring of Vegfr2-luc transgenic mouse is applicable to tracking angiogenesis in vivo.