RESUMO
Salvia miltiorrhiza is a kind of medicinal plant with various pharmacological activities. Few studies on the composition and diversity of rhizosphere microbial communities at different growth stages have been conducted on Salvia miltiorrhiz; in particular, salviorrhiza grows in soil that has been continuously planted for 3 years. The purpose of this study was to understand the changes of soil physicochemical properties of Salvia miltiorrhiza at different growth stages, and to study the composition and diversity of rhizosphere microbial community at different growth stages. Illumina NovaSeq sequencing technology was used to analyze the bacterial 16S rRNA gene and the fungal ITS region in the rhizosphere soil of Salvia miltiorrhiza at different growth stages. The results showed that the dominant bacterial phyla in the Salvia miltiorrhiza rhizosphere were Proteobacteria, Bacteroidetes, Acidobacteria, Firmicutes, Actinobacteria, and Chloroflexi. The dominant fungal phyla were Ascomycota, Mortierellomycota, Basidiomycota, and Rozellomycota. During the growth of Salvia miltiorrhiza, the physical and chemical properties of soil changed. As the Salvia miltiorrhiza grew, the content of available phosphorus, available potassium, pH, nitrate nitrogen, and ammonium nitrogen significantly decreased. Ammonium nitrogen and nitrate nitrogen had a greater impact on the bacterial community structure in the rhizosphere than on the fungal community structure. The work was to reveal differences in the rhizosphere bacterial and fungal community structure during different growth stages of Salvia miltiorrhiza, further understand the changes of rhizosphere microbial ecological characteristics and soil physicochemical properties during the cultivation of Salvia miltiorrhiza.
RESUMO
OBJECTIVE: Muscle dysfunction caused by repetitive work or strain in the neck region can interfere muscle responses. Muscle dysfunction can be an important factor in causing cervical spondylosis. However, there has been no research on how the biomechanical properties of the upper cervical spine change when the suboccipital muscle group experiences dysfunction. The objective of this study was to investigate the biomechanical evidence for cervical spondylosis by utilizing the finite element (FE) approach, thus and to provide guidance for clinicians performing acupoint therapy. METHODS: By varying the elastic modulus of the suboccipital muscle, the four FE models of C0-C3 motion segments were reconstructed under the conditions of normal muscle function and muscle dysfunction. For the two normal condition FE models, the elastic modulus for suboccipital muscles on both sides of the C0-C3 motion segments was equal and within the normal range In one muscle dysfunction FE model, the elastic modulus on both sides was equal and greater than 37 kPa, which represented muscle hypertonia; in the other, the elastic modulus of the left and right suboccipital muscles was different, indicating muscle imbalance. The biomechanical behavior of the lateral atlantoaxial joint (LAAJ), atlanto-odontoid joint (ADJ), and intervertebral disc (IVD) was analyzed by simulations, which were carried out under the six loadings of flexion, extension, left and right lateral bending, left and right axial rotation. RESULTS: Under flexion, the maximum stress in LAAJ with muscle imbalance was higher than that with normal muscle and hypertonia, while the maximum stress in IVD in the hypertonic model was higher than that in the normal and imbalance models. The maximum stress in ADJ was the largest under extension among all loadings for all models. Muscle imbalance and hypertonia did not cause overstress and stress distribution abnormalities in ADJ. CONCLUSION: Muscle dysfunction increases the stress in LAAJ and in IVD, but it does not affect ADJ.