Accurate loss measurement of optical bulk materials with the pulsed cavity ring-down technique.

In a wide range of laser applications, the optical losses of optical materials used in the laser systems are closely linked to the laser-induced damage and laser beam quality deterioration. It is demonstrated in this paper that when the pulsed cavity ring-down (CRD) technique is employed to measure the optical loss of uncoated substrates inserted in the ring-down cavity with normal incidence, the surface reflection of the uncoated substrate causes a significant overestimation of the optical loss. The degree of overestimation increases rapidly with the increasing surface reflectance.

Reduced SARS-CoV-2 infection risk is associated with the use of Seven-Flavor Herb Tea: A multi-center observational study in Shanghai, China.

Objective: Omicron, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, is responsible for numerous infections in China. This study investigates the association between the use of Seven-Flavor Herb Tea (SFHT) and the risk of SARS-CoV-2 infection to develop precise and differentiated strategies for control of the coronavirus disease 2019 (COVID-19).

Methods: This case-control study was conducted at shelter hospitals and quarantine hotels in China.

Safety and feasibility of laparoscopic surgery for colorectal and gastric cancer under the Chinese multi-site practice policy: admittance standards of competence are needed.

Background: The multi-site practice (MSP) policy has been practiced in China over 10 years. This study aimed to investigate the safety and feasibility of performing laparoscopic surgery for colorectal cancer (LSCRC) and gastric cancer (LSGC) under the Chinese MSP policy.

Methods: We collected and analysed the data from 1,081 patients who underwent LSCRC or LSGC performed by one gastrointestinal surgeon in his original hospital ( = 573) and his MSP institutions ( = 508) between January 2017 and December 2020.