The effect of voice training interventions on patients with oropharyngeal dysphagia: a systematic review.

BACKGROUND: Voice training has been proposed as an intervention to improve swallowing function in patients with dysphagia. However, little is known about the effects of voice training on swallowing physiology. OBJECTIVES: This systematic review investigates the effect of voice training on the swallowing function of patients with oropharyngeal dysphagia and provides the theoretical basis for improving the swallowing function and life quality of patients with oropharyngeal dysphagia. DATA SOURCES: A systematic review using a narrative synthesis approach of all published studies was sought with no date restrictions. Five electronic databases (EMBASE, PubMed, CINAHL, Web of Science, and The Cochrane Library) were searched from inception to April 2022. STUDY SELECTION: Eight studies were included. Two researchers screened the literature according to inclusion and exclusion criteria, extracted data, and carried out quality control according to the Cochrane handbook5.1.0. Data were analyzed narratively and descriptively. CONCLUSIONS: In general, statistically significant positive therapy effects were found. Voice training improves the oral and pharyngeal stages of swallowing in patients with neurological causes of dysphagia, such as stroke, and in patients with non-neurological causes of dysphagia, such as head and neck cancer. However, the current literature is limited and further primary research is required to provide more evidence to support voice training intervention in dysphagia.  Future studies could  further refine the content of voice training interventions, increase the number of patients enrolled, assess the long-term effects of voice training interventions and add associated assessments of the quality of life after treatment.

Succession in arbuscular mycorrhizal fungi can be attributed to a chronosequence of Cunninghamia lanceolata.

Arbuscular mycorrhizal (AM) fungi play an important role in plant-fungi communities. It remains a central question of how the AM fungal community changes as plants grow. To establish an understanding of AM fungal community dynamics associated with Chinese fir, Chinese fir with five different growth stages were studied and 60 root samples were collected at the Jiangle National Forestry Farm, Fujian Province. A total of 76 AM fungal operational taxonomic units (OTUs) were identified by high-throughput sequencing on an Illumina Miseq platform. The genera covered by OTUs were Glomus, Archaeospora, Acaulospora, Gigaspora and Diversispora. Glomus dominated the community in the whole stage. The number and composition of OTUs varied along with the host plant growth. The number of OTUs showed an inverted V-shaped change with the host plant age, and the maximum occurred in 23-year. Overall, the basic species diversity and richness in this study were stable. Non-metric multi-dimensional scaling (NMDS) analysis based on bray-curtis distance revealed that there were remarkable differentiations between the 9-year and other stages. Besides, AM fungal community in 32-year had a significant difference with that of 23-year, while no significant difference with that of 45-year, suggesting that 32-year may be a steady stage for AM fungi associated with Chinese fir. The cutting age in 32-year may be the most favorable for microbial community. The pH, total N, total P, total K, available N, available P, available K, organic matter and Mg varied as the Chinese fir grows. According to Mantel test and redundancy analysis, available N, available P, K and Mg could exert significant influence on AM fungal communities, and these variables explained 31% of variance in the composition of AM fungal communities.