对歌唱发声的几个重要感觉的把握与理解

文章从客观角度力图解释歌唱发声过程中的诸如歌唱发声与话语声的区别,歌唱时的对抗控制感觉等问题。并从生理学和歌唱感觉的主客观关联上进行了一定探讨,从中寻找出一条声乐理论研究的新路子。     

头孢匹胺治疗下呼吸道感染72例临床观察

将72例确诊为下呼吸道感染的患者随机分成2组,在常规治疗基础上,治疗组36例,静脉滴注头孢匹胺1g,每日两次;对照组36例静脉滴注头孢尼西2g,每日一次,两组疗程均为7～14天,观察两组的临床疗效.治疗组和对照组临床治愈率分别是94%和83%,总有效率分别为97%和88%,两组数据比较有统计学意义(P<0.05).结果表明头孢匹胺是第三代头孢菌素,安全抗菌活性强.在下呼吸道感染的治疗中疗效确切.     

Seasonal coronaviruses and SARS-CoV-2: effects of preexisting immunity during the COVID-19 pandemic

Although the coronavirus disease 2019 (COVID-19) epidemic is still ongoing, vaccination rates are rising slowly and related treatments and drugs are being developed. At the same time, there is increasing evidence of preexisting immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans, mainly consisting of preexisting antibodies and immune cells (including T cells and B cells). The presence of these antibodies is mainly due to the seasonal prevalence of four common coronavirus types, especially OC43 and HKU1. The accumulated relevant evidence has suggested that the target of antibodies is mainly the S2 subunit of S protein, followed by evolutionary conservative regions such as the nucleocapsid (N) protein. Additionally, preexisting memory T and B cells are also present in the population. Preexisting antibodies can help the body protect against SARS-CoV-2 infection, reduce the severity of COVID-19, and rapidly increase the immune response post-infection. These multiple effects can directly affect disease progression and even the likelihood of death in certain individuals. Besides the positive effects, preexisting immunity may also have negative consequences, such as antibody-dependent enhancement (ADE) and original antigenic sin (OAS), the prevalence of which needs to be further established. In the future, more research should be focused on evaluating the role of preexisting immunity in COVID-19 outcomes, adopting appropriate policies and strategies for fighting the pandemic, and vaccine development that considers preexisting immunity.