[Application of Novel Down-sampling Method in Retinal Vessel Segmentation].

Accurate segmentation of retinal blood vessels is of great significance for diagnosing, preventing and detecting eye diseases. In recent years, the U-Net network and its various variants have reached advanced level in the field of medical image segmentation. Most of these networks choose to use simple max pooling to down-sample the intermediate feature layer of the image, which is easy to lose part of the information, so this study proposes a simple and effective new down-sampling method Pixel Fusion-pooling (PF-pooling), which can well fuse the adjacent pixel information of the image. The down-sampling method proposed in this study is a lightweight general module that can be effectively integrated into various network architectures based on convolutional operations. The experimental results on the DRIVE and STARE datasets show that the F1-score index of the U-Net model using PF-pooling on the STARE dataset improved by 1.98%. The accuracy rate is increased by 0.2%, and the sensitivity is increased by 3.88%. And the generalization of the proposed module is verified by replacing different algorithm models. The results show that PF-pooling has achieved performance improvement in both Dense-UNet and Res-UNet models, and has good universality.

Metabolome profiling of plasma reveals different metabolic responses to acute cold challenge between Inner-Mongolia Sanhe and Holstein cattle.

Low-temperature conditions influence cattle productivity and survivability. Understanding the metabolic regulations of specific cattle breeds and identifying potential biomarkers related to cold challenges are important for cattle management and optimization of genetic improvement programs. In this study, 28 Inner-Mongolia Sanhe and 22 Holstein heifers were exposed to -25°C for 1 h to evaluate the differences in metabolic mechanisms of thermoregulation. In response to this acute cold challenge, altered rectal temperature was only observed in Holstein cattle. Further metabolome analyses showed a greater baseline of glycolytic activity and mobilization of AA in Sanhe cattle during normal conditions. Both breeds responded to the acute cold challenge by altering their metabolism of volatile fatty acids and AA for gluconeogenesis, which resulted in increased glucose levels. Furthermore, Sanhe cattle mobilized the citric acid cycle activity, and creatine and creatine phosphate metabolism to supply energy, whereas Holstein cattle used greater AA metabolism for this purpose. Altogether, we found that propionate and methanol are potential biomarkers of acute cold challenge response in cattle. Our findings provide novel insights into the biological mechanisms of acute cold response and climatic resilience, and will be used as the basis when developing breeding tools for genetically selecting for improved cold adaptation in cattle.

Preliminary Study of an Adjustable, Wearable, Noninvasive Vest Providing Chest Compression to Assist with Breathing.

Respiratory muscle paralysis caused by acute cervical spinal cord injury usually leads to pulmonary ventilation dysfunction and even death from respiratory failure. In addition to invasive treatments such as mechanical ventilation, the utilization of noninvasive respiratory support equipment plays an important role in long-term assisted breathing. In this study, we describes a wearable, noninvasive vest with adjustable pressure that enables assisted breathing and with an automatic alarm, and we aims to explore its safety and effectiveness on healthy adult participants. The vest monitors the human heart rate and the blood oxygen index data in real time, the alarm is automatically activated when the data is abnormal. Eight healthy participants had no obvious discomfort during the test while wearing the vest. Lung volumes, antero-posterior diameters, and left-right diameters at the second, fourth, and sixth ribs levels were acquired before and after inflation of the vest airbag, the data acquired by the imaging analysis using chest computed tomography showed significant differences before and after the inflation (p < 0.05). Thus, The vest designed for this study can achieve uniform and effective compression of the thorax, significantly changed the size of the thorax and lungs. It is expected to be applied as noninvasive support for patients with respiratory dysfunction.