Impacts of the COVID-19 pandemic on Chinese assisted reproductive technology institutions and human sperm banks: reflections in the post-pandemic era.

OBJECTIVE: The COVID-19 pandemic has been the most serious public health emergency encountered in modern assisted reproductive technology (ART) development. In order to identify lessons learned, this study reviews the effect of the pandemic on ART institutions and human sperm banks in China, and summarizes the experiences and reflections of Chinese scholars post-pandemic era. METHODS: This review is based on multiple consensus statements on the COVID-19 pandemic issued by Chinese experts as well as current national regulations and principles in ART institutions and human sperm banks to document the current situation of ART services in China, describe the impact of the pandemic on these services, and offer Chinese reflections on worrying issues in the post-pandemic era. RESULTS: China reached one million ART cycles in 2016, and there are currently 540 ART medical institutions and 27 human sperm banks, with 540 licensed for AIH, 91 for AID, 415 for conventional IVF and ICSI and 85 for PGT. Of these, only 4 institutions carry out 10,000 cycles or more annually, and the proportion of institutions with less than 1,000 cycles has reached 66%, which means that a considerable number of ART institutions are still not saturated. As a consequence of the COVID-19 pandemic, 63.6% of ART providers and 95.5% of human sperm banks suspended operations. By the end of May 2020, China, as an early country affected by the pandemic achieved a national resumption rate of ART medical services of 99.2% and that of human sperm banks of 100.0%. Reports from the first and largest human sperm bank in China showed that qualification, semen concentration and sperm viability rates measured at primary screening have significantly decreased post-pandemic. Much like in other countries, Chinese experts developed a consensus on prevention and control measures during the pandemic. In principle, all ART activities should be suspended during acute phases of infection spread. Chinese scholars highlight that attention should be paid to young patients with fertility requirements during and after COVID-19, and emphasize the importance of fertility evaluation and clinical intervention. In addition, couples should be reminded that during ART treatment, disinfectants should not be used excessively to minimize risks of damaging the reproductive system, gametes and zygotes. At the same time, timely and reasonable guidance for tackling negative emotions from stress response is needed to provide reassurance and to avoid irrational fear and excessive stress. Seminal parameters should be re-examined 2 months after SARS-CoV-2 vaccination, and ART treatments recommenced if no abnormalities are detected. CONCLUSIONS: Given the growing frequency of outbreaks of global infectious diseases in recent years, ART institutions and human sperm banks should pay attention to improving their prevention and control capabilities. To a certain extent, decisions and measures adopted in China during COVID-19 pandemic are worthy of recognition and acceptance. Chinese scholars have discussed, proactively responded to and understand the key issues surrounding ART development during the pandemic with the aim of contributing to the substantial progress and healthy development of ART services in the world.

Evaluation of a Hybrid Underwater Sound-Absorbing Metastructure by Using the Transfer Matrix Method.

In this study, we designed a novel hybrid underwater sound-absorbing material of the metastructure that contains a viscoelastic substrate with a microperforated panel. Two types of sound-absorbing metastructures were combined to achieve satisfactory sound absorption performance in the low-frequency range. A homogenized equivalent layer and the integrated transfer matrix method were used to theoretically evaluate the sound absorption performance of the designed nonhomogeneous hybrid metastructure. The theoretical results were then compared with the results obtained using the finite-element method. The designed hybrid sound-absorbing metastructure exhibited two absorption peaks because of its different sound-absorbing mechanisms. The acoustic performance of the developed metastructure is considerably better than that of a traditional sound absorber, and the sound absorption coefficient of the developed metastructure is 0.8 in the frequency range of 3-10 kHz. In addition, an adjustment method for the practical underwater application of the designed metastructure is described in this research. Further studies show that the sound absorption coefficient of the adjusted metastructure still has 0.75 in the frequency range of 3-10 kHz, which indicates that this metastructure has the potential to be used as an underwater sound-absorbing structure. The results of this study can be used as a reference in the design of other novel hybrid underwater sound-absorbing structures.

Current status and reflections on fertility preservation in China.

PURPOSE: With the progress of medical technology and renovated conception of fertility, the prospective studies and practice of fertility preservation are drawing more and more attention from medical workers. With the largest population of over 1.4 billion, China makes the experience accumulated in fertility preservation efforts even more relevant. This article summarizes China's experience and shares it with the world to promote the healthy development of fertility preservation. METHODS: This study was based on multiple Chinese expert consensuses on fertility preservation issued in 2021 and the current national regulations and principles, compared with the latest advice and guidelines issued by global reproductive authorities such as the ASRM and ESHRE. Summarize the experience and reflection of Chinese scholars in the process of fertility preservation. RESULTS: This study reports on the current situation of fertility preservation in China, sharing the Chinese experience gained in the process of development, and offering Chinese reflections on worrying issues. CONCLUSION: Fertility preservation is a medical and social issue of reproductive health security, which is conducive to the sound development of the world population and social production.