RESUMEN
The two-way quantum clock synchronization has been shown to provide femtosecond-level synchronization capability and security against symmetric delay attacks, thus becoming a prospective method to compare and synchronize distant clocks with enhanced precision and safety. In this letter, a field test of two-way quantum synchronization between a H-maser and a Rb clock linked by a 7 km-long deployed fiber is implemented by using time-energy entangled photon-pair sources. Limited by the intrinsic frequency stability of the Rb clock, the achieved time stability at 30 s is measured as 32 ps. By applying a fiber-optic microwave frequency transfer technology to build frequency syntonization between the separated clocks, the limit set by the intrinsic frequency stability of the Rb clock is overcome. A significantly improved time stability of 1.9 ps at 30 s is achieved, which is mainly restrained by the low number of acquired photon pairs due to the low sampling rate of the utilized coincidence measurement system. Such implementation demonstrates the high practicability of the two-way quantum clock synchronization method for promoting field applications.
RESUMEN
In fiber-based quantum information processing with energy-time entangled photon pairs, optimized dispersion compensation is vital to preserve the strong temporal correlation of the photon pairs. We propose and experimentally verify that, by simply tuning the wavelength of the entangled photon pairs, nonlocal dispersion cancellation (NDC) can provide a widely flexible and finely adjustable solution for optimizing the dispersion compensation, which cannot be reached with the traditional local dispersion cancellation (LDC) instead. By way of example, when a 50 km-long single-mode fiber (SMF) is dispersion compensated by a 6.2-km-long commercial dispersion compensating fiber (DCF) based on the LDC configuration, it will lead to an almost invariant over-compensation in the wavelength range of 1500-1600 nm which restricts the observed temporal coincidence width of the self-developed energy-time entangled photon-pairs source to a minimum of â¼110 ps. While in the NDC configuration, the dispersion compensation can be readily optimized by tuning the signal wavelength to 1565.7 nm and a minimum coincidence width of 86.1 ± 0.7 ps is observed, which is mainly limited by the jitter of the single-photon detection system. Furthermore, such optimized dispersion compensation can also be achieved as the fiber length varies from 48 km to 60 km demonstrating the wide flexibility of NDC. Thanks to these capabilities, elaborate dispersion compensation modules are no longer required, which makes NDC a more versatile tool in fiber-based quantum information and metrology applications.
RESUMEN
AIM: Acute appendicitis is one of the most common causes of acute abdomen in pediatric surgery. The purpose of this study was to observe the effects of integrated rapid rehabilitation nursing in children with laparoscopic appendectomy (LA) during the perioperative period. METHODS: A total of 200 children with appendicitis who underwent LA in our hospital from January 2022 to January 2023 were retrospectively selected as the study subjects. According to the nursing mode, they were divided into a control group (n = 100) and an observation group (n = 100). The control group was treated with routine nursing intervention, and the observation group was treated with an integrated rapid rehabilitation nursing intervention. Perioperative indices (operation time, first postoperative exhaust time, length of hospital stay) were recorded and compared between the two groups. The visual analog scale (VAS) was used to score the two groups at 6 h, 12 h, 24 h, and 48 h after surgery, and the pain degree of the children was quantitatively evaluated. The levels of serum stress response indices (cortisol (Cor), norepinephrine (NE), and adrenocorticotropic hormone (ACTH)) in the two groups were measured. The incidence of postoperative complications, improvement of postoperative quality of life, and nursing satisfaction were compared between the two groups. RESULTS: The operation time, first postoperative exhaust time, and hospitalization time in the observation group were significantly shorter than those in the control group (p < 0.05), and the VAS scores of the patients in the observation group were lower than those in the control group at each time point of 6 h, 12 h, 24 h, and 48 h after surgery (p < 0.05). One hour after surgery, the serum Cor, NE, and ACTH levels of the two groups of patients were significantly higher than those before surgery, and the levels for the observation group were significantly lower than those of the control group (p < 0.05). After treatment, the quality of life scores of patients in both groups was significantly higher than before treatment, and the quality of life scores of patients in the observation group was significantly higher than that of the control group (p < 0.05). The postoperative complication rate of the observation group was 3.00% (3/100), which was significantly lower than that of the control group (13.00% (13/100)) (χ2 = 6.793, p = 0.009). The nursing satisfaction of the observation group was 95.00% (95/100), which was significantly higher than that of the control group (79.00% (79/100)) (χ2 = 11.317, p = 0.001). CONCLUSIONS: The integrated rapid rehabilitation nursing management mode is an intervention that can effectively alleviate the effects of LA on stress reactions and pain in children with appendicitis. It can effectively reduce the incidence of postoperative complications and improve the patient's nursing satisfaction, allowing children with appendicitis to recover as soon as possible after surgery, and can improve patients' quality of life. It helps to improve the overall clinical efficacy, and the treatment process is simple to operate, relatively safe and reliable, has high use value, and is worthy of further promotion in clinical treatment.