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Continuous cropping obstacle is the bottleneck of medicinal plant cultivation, which seriously affects the quality and yield of medicinal materials. The research on the mechanism of continuous cropping obstacle has evolved from soil physical and chemical properties and allelopathy in the 1970s to the changes of rhizosphere microenvironment and plant response mechanism at present. According to the available studies in this field and our previous research work, we systematically analyzed the mechanism of rhizosphere exudate-mediated microbial community reconstruction in the soil of the medicinal plants in continuous cropping. Specifically, rhizosphere exudates, providing the carbon source and energy for microbial growth, act as inducers or repellents to induce microbial growth or transfer, thereby changing the physicochemical properties (such as acidity) of rhizosphere soil and further altering the structure of rhizosphere microbial community. Further, we comprehensively discussed the ways of synergism between rhizosphere exudates and soil microorganisms in causing harm to the medicinal plants in continuous cropping. That is, rhizosphere exudates mediate the infection of the rhizosphere by pathogenic microorganisms, increase the susceptibility of the nearby plants, inhibit the defense of the host plants, and protect the pathogens to occupy the dominant niche. The synergistic interaction results in the release of more pathogenic factors such as mycotoxins by rhizosphere pathogens, enhanced toxicity of rhizosphere allelochemicals, and deterioration of soil physical and chemical properties. This paper summarizes the role of interaction between rhizosphere exudates and soil microorganisms in the formation of continuous cropping obstacles, aiming to provide a new research idea for revealing the formation mechanism as well as the theoretical support for overcoming continuous cropping obstacles of medicinal plants.
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Background@#Feline calicivirus (FCV) is a common pathogen of felids, and FCV vaccination is regularly practiced. The genetic variability and antigenic diversity of FCV hinder the effective control and prevention of infection by vaccination. Improved knowledge of the epidemiological characteristics of FCV should assist in the development of more effective vaccines. @*Objectives@#This study aims to determine the prevalence of FCV in a population of cats with FCV-suspected clinical signs in Hangzhou and to demonstrate the antigenic and genetic relationships between vaccine status and representative isolated FCV strains. @*Methods@#Cats (n = 516) from Hangzhou were investigated between 2018 and 2020. The association between risk factors and FCV infection was assessed. Phylogenetic analyses based on a capsid coding sequence were performed to identify the genetic relationships between strains. In vitro virus neutralization tests were used to assess antibody levels against isolated FCV strains in client-owned cats. @*Results@#The FCV-positive rate of the examined cats was 43.0%. Risk factors significantly associated with FCV infection were vaccination status and oral symptoms. Phylogenetic analysis revealed a radial phylogeny with no evidence of temporal or countrywide clusters. There was a significant difference in the distribution of serum antibody titers between vaccinated and unvaccinated cats. @*Conclusions@#This study revealed a high prevalence and genetic diversity of FCV in Hangzhou. The results indicate that the efficacy of FCV vaccination is unsatisfactory. More comprehensive and refined vaccination protocols are an urgent and unmet need.
RESUMEN
Background@#Feline calicivirus (FCV) is a common pathogen of felids, and FCV vaccination is regularly practiced. The genetic variability and antigenic diversity of FCV hinder the effective control and prevention of infection by vaccination. Improved knowledge of the epidemiological characteristics of FCV should assist in the development of more effective vaccines. @*Objectives@#This study aims to determine the prevalence of FCV in a population of cats with FCV-suspected clinical signs in Hangzhou and to demonstrate the antigenic and genetic relationships between vaccine status and representative isolated FCV strains. @*Methods@#Cats (n = 516) from Hangzhou were investigated between 2018 and 2020. The association between risk factors and FCV infection was assessed. Phylogenetic analyses based on a capsid coding sequence were performed to identify the genetic relationships between strains. In vitro virus neutralization tests were used to assess antibody levels against isolated FCV strains in client-owned cats. @*Results@#The FCV-positive rate of the examined cats was 43.0%. Risk factors significantly associated with FCV infection were vaccination status and oral symptoms. Phylogenetic analysis revealed a radial phylogeny with no evidence of temporal or countrywide clusters. There was a significant difference in the distribution of serum antibody titers between vaccinated and unvaccinated cats. @*Conclusions@#This study revealed a high prevalence and genetic diversity of FCV in Hangzhou. The results indicate that the efficacy of FCV vaccination is unsatisfactory. More comprehensive and refined vaccination protocols are an urgent and unmet need.
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Objective To investigate the level and influencing factors of quality of life in patients with osteoradionecrosis of the jaws (ORNJ) in order to provide theory basis for nursing intervention. Methods Ninety-five patients hospitalized from January 2015 to Febury 2017 and participated in the investigation by a convenient sampling method. The functional assessment of cancer therapy-head and neck (FACT-H&N), social support rating scale (SSRS) and general information questionnaire were used to assess the quality of life, social support and basic information in ORNJ patients in our hospital respectively. Results The score of quality of life was (79.99 ±15.72). The index value of common module of quality of life was higher than that of additional concern. The average scores of each dimension of common module from low to high were as follows: functional well-being, social/family well-being, physical well-being and emotional well-being. The multiple linear regression analysis showed that the influencing factors of quality of life were social support, severe mouth opening difficulty (grade Ⅲ and Ⅳ), the course of primary disease (3 ～5 years, 5 ～10 years), which explained 35.6％variation in the quality of life. Conclusions The quality of life of ORNJ patients is generally lower than that of other head and neck cancer patients. The social support, severe mouth opening difficulty and course of primary disease can affect the patients' quality of life.The smaller the mouth opening (≤1 cm), the longer the course of primary disease (3～5 years) and the worse the quality of life is. Thus, nursing staff should pay attention to the quality of life of ORNJ patients and give prospective nursing intervention to improve the quality of life according to the characteristics of the development of the disease.