Single-image night haze removal based on color channel transfer and estimation of spatial variation in atmospheric light

The visible-light imaging system used in military equipment is often subjected to severe weather conditions, such as fog, haze, and smoke, under complex lighting conditions at night that significantly degrade the acquired images. Currently available image defogging methods are mostly suitable for environments with natural light in the daytime, but the clarity of images captured under complex lighting conditions and spatial changes in the presence of fog at night is not satisfactory. This study proposes an algorithm to remove night fog from single images based on an analysis of the statistical characteristics of images in scenes involving night fog. Color channel transfer is designed to compensate for the high attenuation channel of foggy images acquired at night. The distribution of transmittance is estimated by the deep convolutional network DehazeNet, and the spatial variation of atmospheric light is estimated in a point-by-point manner according to the maximum reflection prior to recover the clear image. The results of experiments show that the proposed method can compensate for the high attenuation channel of foggy images at night, remove the effect of glow from a multi-color and non-uniform ambient source of light, and improve the adaptability and visual effect of the removal of night fog from images compared with the conventional method.

Extracellular matrix from human umbilical cordderived mesenchymal stem cells as a scaffold for peripheral nerve regeneration

The extracellular matrix,which includes collagens,laminin,or fibronectin,plays an important role in peripheral nerve regeneration.Recently,a Schwann cell-derived extracellular matrix with classical biomaterial was used to mimic the neural niche.However,extensive clinical use of Schwann cells remains limited because of the limited origin,loss of an autologous nerve,and extended in vitro culture times.In the present study,human umbilical cord-derived mesenchymal stem cells(h UCMSCs),which are easily accessible and more proliferative than Schwann cells,were used to prepare an extracellular matrix.We identified the morphology and function of h UCMSCs and investigated their effect on peripheral nerve regeneration.Compared with a non-coated dish tissue culture,the h UCMSC-derived extracellular matrix enhanced Schwann cell proliferation,upregulated gene and protein expression levels of brain-derived neurotrophic factor,glial cell-derived neurotrophic factor,and vascular endothelial growth factor in Schwann cells,and enhanced neurite outgrowth from dorsal root ganglion neurons.These findings suggest that the h UCMSC-derived extracellular matrix promotes peripheral nerve repair and can be used as a basis for the rational design of engineered neural niches.

Different protein expression patterns in rat spinal nerves during wallerian degeneration assessed using isobaric tags for relative and absolute quantitation proteomics profiling

Sensory and motor nerve fibers of peripheral nerves have different anatomies and regeneration functions after injury. To gain a clear understanding of the biological processes behind these differences, we used a labeling technique termed isobaric tags for relative and absolute quantitation to investigate the protein profiles of spinal nerve tissues from Sprague-Dawley rats. In response to Wallerian degeneration, a total of 626 proteins were screened in sensory nerves, of which 368 were upregulated and 258 were downregulated. In addition, 637 proteins were screened in motor nerves, of which 372 were upregulated and 265 were downregulated. All identified proteins were analyzed using the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis of bioinformatics, and the presence of several key proteins closely related to Wallerian degeneration were tested and verified using quantitative real-time polymerase chain reaction analyses. The differentially expressed proteins only identified in the sensory nerves were mainly relevant to various biological processes that included cell-cell adhesion, carbohydrate metabolic processes and cell adhesion, whereas differentially expressed proteins only identified in the motor nerves were mainly relevant to biological processes associated with the glycolytic process, cell redox homeostasis, and protein folding. In the aspect of the cellular component, the differentially expressed proteins in the sensory and motor nerves were commonly related to extracellular exosomes, the myelin sheath, and focal adhesion. According to the Kyoto Encyclopedia of Genes and Genomes, the differentially expressed proteins identified are primarily related to various types of metabolic pathways. In conclusion, the present study screened differentially expressed proteins to reveal more about the differences and similarities between sensory and motor nerves during Wallerian degeneration. The present findings could provide a reference point for a future investigation into the differences between sensory and motor nerves in Wallerian degeneration and the characteristics of peripheral nerve regeneration. The study was approved by the Ethics Committee of the Chinese PLA General Hospital, China(approval No. 2016-x9-07) in September 2016.

Cerebral venous sinus thrombosis in pregnancy: A case report

BACKGROUND Cerebral venous thrombosis(CVT)is a rare but life-threatening disease in pregnant women.Anticoagulation is the first-line therapy for CVT management.However,some patients have poor outcomes despite anticoagulation.Currently,the endovascular treatment of CVT in pregnant women remains controversial.We report a rare case of CVT in a pregnant woman who was successfully treated with two stent retriever devices.CASE SUMMARY The patient was a 29-year-old pregnant woman.She was first diagnosed with hyperemesis gravidarum due to severe nausea and vomiting for one week.As the disease progressed,she developed acute left hemiplegia.Imaging confirmed the diagnosis of superior sagittal sinus,right transverse sinus and sinus sigmoideus thrombosis.As anticoagulant therapy was ineffective,she underwent thrombectomy.After the mechanical thrombectomy,her headache diminished.Three weeks later,the patient was completely independent.At a 3-mo follow-up,no relapse of symptoms was observed.CONCLUSION Mechanical thrombectomy may be an effective alternative therapy for CVT in pregnant women if anticoagulation therapy fails.