Musk secretion in muskrats(Ondatra zibethicus L.):association with lipid and cholesterol metabolism-related pathways

Male muskrats(Ondatra zibethicus L.)secrete musk from their scent glands during musk secretion season.Musk plays an important role as a communication pheromone during the breeding season.In this study,gas chromatography–mass spectrometry(GC–MS)was used to analyze the main components of musk.The GC–MS results after methyl esterification showed that 71.55%of the musk is composed of fatty acids.The other components of muskrat musk include cholesterol(9.31%)and other organics.Transcriptome comparison between musk secretion and non-secretion seasons showed significant changes in the scent glands for 53 genes involved in fatty acid and cholesterol synthesis and metabolism regulatory pathways,which include fatty acid biosynthesis,elongation,and metabolism;steroid biosynthesis;steroid hormone biosynthesis pathways.A reverse transcription–polymerase chain reaction analysis confirmed these detected changes.Overall,our results indicated that lipid synthesis and metabolism play important roles in musk compound synthesis by providing energy for musk production,and the produced musk provides a mechanism for male muskrats to communicate with females during the breeding season.

Near-field acoustic levitation and applications to bearings:a critical review

The importance to industry of non-contact bearings is growing rapidly as the demand for highspeed and high-precision manufacturing equipment increases.As a recently developed non-contact technology,near-field acoustic levitation(NFAL)has drawn much attention for the advantages it offers,including no requirement for an external pressurized air supply,its compact structure,and its ability to adapt to its environment.In this paper,the working mechanism of NFAL is introduced in detail and compared to all existing non-contact technologies to demonstrate its versatility and potential for practical applications in industry.The fundamental theory of NFAL,including gas film lubrication theory and acoustic radiation pressure theory is presented.Then,the current stateof-the-art of the design and development of squeeze film air bearings based on NFAL is reviewed.Finally,future trends and obstacles to more widespread use are discussed.

Crack identification method of highway tunnel based on image processing

In this paper,the images of tunnel surface are obtained by tunnel lining rapid inspection system,and tunnel crack forest dataset(TCFD)is established.The disaster characteristics of tunnel cracks are analyzed and summarized.Solutions of tunnel crack segmentation(TCS)method are developed for the detection and recognition of cracks on tunnel lining.According to the image features of the tunnel lining and the optical principal of detection equipment,effective image pre-processing steps are carried out before crack extraction.The tunnel image of TCFD is divided into appropriate number of blocks to magnify the local features of tunnel cracks.Local threshold segmentation method is used to traverse the blocks successively,and the first target block with crack is obtained.The seed in the target block were obtained by adaptive localization method and mapped to the whole image.Region growing is performed through crack seed until complete tunnel crack is extracted.The results show that the precision,recall rate and F-measure of tunnel cracks under the TCS method can reach 92.58%,93.07%and 92.82%without strong interference.According to the binary images processed by TCS method,the projection images of different types of tunnel cracks and their respective laws are obtained.Furthermore,the TCS method is implemented and deployed as a GUI software application.

Pulmonary rehabilitation restores limb muscle mitochondria and improves the intramuscular metabolic profile

Background: Exercise, as the cornerstone of pulmonary rehabilitation, is recommended to chronic obstructive pulmonary disease (COPD) patients. The underlying molecular basis and metabolic process were not fully elucidated. Methods: Sprague-Dawley rats were classified into five groups: non-COPD/rest ( n = 8), non-COPD/exercise ( n = 7), COPD/rest ( n = 7), COPD/medium exercise ( n = 10), and COPD/intensive exercise ( n = 10). COPD animals were exposed to cigarette smoke and lipopolysaccharide instillation for 90 days, while the non-COPD control animals were exposed to room air. Non-COPD/exercise and COPD/medium exercise animals were trained on a treadmill at a decline of 5° and a speed of 15 m/min while animals in the COPD/intensive exercise group were trained at a decline of 5° and a speed of 18 m/min. After eight weeks of exercise/rest, we used ultrasonography, immunohistochemistry, transmission electron microscopy, oxidative capacity of mitochondria, airflow-assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI), and transcriptomics analyses to assess rectal femoris (RF). Results: At the end of 90 days, COPD rats’ weight gain was smaller than control by 59.48 ± 15.33 g ( P = 0.0005). The oxidative muscle fibers proportion was lower ( P < 0.0001). At the end of additional eight weeks of exercise/rest, compared to COPD/rest, COPD/medium exercise group showed advantages in weight gain, femoral artery peak flow velocity (Δ58.22 mm/s, 95% CI: 13.85-102.60 mm/s, P = 0.0104), RF diameters (Δ0.16 mm, 95% CI: 0.04-0.28 mm, P = 0.0093), myofibrils diameter (Δ0.06 μm, 95% CI: 0.02-0.10 μm, P = 0.006), oxidative muscle fiber percentage (Δ4.84%, 95% CI: 0.15-9.53%, P = 0.0434), mitochondria oxidative phosphorylate capacity ( P < 0.0001). Biomolecules spatial distribution in situ and bioinformatic analyses of transcriptomics suggested COPD-related alteration in metabolites and gene expression, which can be impacted by exercise. Conclusion: COPD rat model had multi-level structure and function impairment, which can be mitigated by exercise.

Characterization of intestinal microbiota and fecal cortisol,T3,and IgA in forest musk deer(Moschus berezovskii)from birth to weaning

Analysis of the intestinal microbiota and physiological parameters in mammalian infancy can reveal health status.In this study,we used a combination of molecular and immunochemical approaches to assess fecal microbiota as well as Cortisol(Cor),Triiodothyronine(T3),and immunoglobulin A(IgA)levels of young forest musk deer(FMD),from birth to one month after weaning(7 days of age–110 days of age).During development as the diet of FMD changes from consuming milk to eating plants,the richness and diversity of intestinal microbiota of young FMD increased significantly.Cor levels remained unchanged throughout early development while significantly increased after weaning,T3 and IgA initially were derived from milk during lactation,significantly decreased after weaning.Correlation network analysis showed that the community of food-oriented microbes were highly structured and that many genera were correlated.Overall,this study provides scientific insights into effective management strategies for the protection of FMD population.