Confirmation of Dissipative Sensing Enhancement in a Microresonator Using Multimode Input.

Optical microresonators have proven to be especially useful for sensing applications. In most cases, the sensing mechanism is dispersive, where the resonance frequency of a mode shifts in response to a change in the ambient index of refraction. It is also possible to conduct dissipative sensing, in which absorption by an analyte causes measurable changes in the mode linewidth and in the throughput dip depth. If the mode is overcoupled, the dip depth response can be more sensitive than the linewidth response, but overcoupling is not always easy to achieve. We have recently shown theoretically that using multimode input to the microresonator can enhance the dip-depth sensitivity by a factor of several thousand relative to that of single-mode input and by a factor of nearly 100 compared to the linewidth sensitivity. Here, we experimentally confirm these enhancements using an absorbing dye dissolved in methanol inside a hollow bottle resonator. We review the theory, describe the setup and procedure, detail the fabrication and characterization of an asymmetrically tapered fiber to produce multimode input, and present sensing enhancement results that agree with all the predictions of the theory.

Clinical effects of robot-assisted esophageal hiatal hernia repair and laparoscopic esophageal hiatal hernia repair: a retrospective comparative study / 中华外科杂志

Objective: To analyze the short-term clinical effects of robot-assisted and laparoscopic repair of the hiatal hernia. Methods: The clinical data of 56 patients underwent minimally invasive hiatal hernia repair from January 2021 to January 2022 in the Department of Minimally Invasive Surgery, Hernias and Abdominal Wall Surgery, People's Hospital of Xinjiang Uygur Autonomous Region were retrospectively analyzed. There were 32 males and 24 females, aging (59.7±10.7) years (range: 28 to 75 years). All patients were divided into laparoscopy group (n=27) and robot group (n=29) according to surgical procedures. Perioperative conditions, hospital stay, and improvement in symptoms before and after surgery were compared between the two groups by the t test, Wilcoxon rank-sum test and χ2 test. Results: All surgical procedures were successfully completed, without conversion to laparotomy or change in operation mode. There were no serious complications related to the operation. The intraoperative blood loss of the robot group was less than that of the laparoscopic group (M (IQR)): (20 (110) ml vs. 40 (80) ml, Z=-4.098, P<0.01). The operation time ((111.7±33.6) minutes vs. (120.4±35.0) minutes, t=-0.943, P=0.350) and hospitalization time ((3.9±1.4) days vs. (4.7±1.9) days, t=-1.980, P=0.053) of the robot group and the laparoscopic group were similar. Follow-up for 12 months after the operation showed no postoperative complications and recurrence. The score of the health-related quality of life questionnaire for gastroesophageal reflux disease in the robot group decreased from 10.8±2.8 before the operation to 6.5±0.6 after the operation, and that in the laparoscopic group decreased from 10.6±2.1 before the operation to 6.3±0.6 after the operation. There was no difference in the influence of different surgical methods on the change in score (t=0.030,P=0.976). Conclusion: Compared with laparoscopic repair of the hiatal hernia, robot-assisted hiatal hernia repair has the advantages of less bleeding, rapid postoperative recovery and good short-term effect.

Cross-polarization coupling of whispering-gallery modes due to the spin-orbit interaction of light.

Light can couple between two orthogonally polarized whispering-gallery modes of a microresonator; the effect is easily observable when those modes are frequency degenerate, and can result in coupled-mode induced transparency (CMIT). Experimental observations of CMIT show that the cross-polarization coupling (CPC) strength is typically 10-8-10-7 per round trip. It is shown in this Letter that polarization rotation resulting from optical spin-orbit interaction through the experimentally realistic asymmetry of a microresonator about its equator can produce CPC with strengths in the same range as observed in experiments.

[Efficacy comparison of laparoscopic Nissen, Toupet and Dor fundoplication in the treatment of hiatal hernia complicated with gastroesophageal reflux disease].

OBJECTIVE: To compare the efficacy and safety among laparoscopic Nissen, Toupet and Dor fundoplication in the treatment of hiatal hernia complicated with gastroesophageal reflux disease (GERD). METHODS: Clinical data of 276 patients of hiatal hernia complicated with GERD undergoing operation in our hospital from December 2012 to January 2015 were retrospectively analyzed, including 149 patients of laparoscopic Nissen fundoplication (Nissen group), 41 of laparoscopic Toupet fundoplication (Toupet group), and 86 patients of laparoscopic Dor fundoplication (Dor group). Esophageal reflux status, esophageal manometry, GERD Q rating scale, and postoperative recovery were compare among the three groups. RESULTS: Reflux status was improved significantly in the three groups after operation(all P<0.05),except that the efficacy in reducing reflux episodes and reflux longest time was not obvious in Toupet group(P>0.05). There were no significant differences in postoperative reflux time, acid reflux time ratio, reflux longest time ratio, DeMeester score among the three groups (all P>0.05). Pairwise comparison showed that Dor group was significantly better than Toupet group in reducing the number of reflux episode(14.36±10.58 vs. 29.83±19.71) and long-reflux (0.64±0.21 vs. 6.20±3.48)(both P<0.05), but Nissen group was better than these two groups in reducing the number of long-reflux (0.38±0.16, P<0.05). As compared to pre-operation, the postoperative esophageal sphincter pressure and residual pressure increased significantly, and the relaxation rate reduced significantly (all P<0.05), while the episode of ineffective swallowing increased significantly in Toupet group (11.25±2.04 vs. 6.36±3.26, P<0.05). The contrast in esophageal manometry between Toupet and Dor group showed that Dor group was better than Toupet group in the recovery of lower esophageal sphincter pressure (mean resting breathing) [(20.69±13.95) mmHg vs.(12.91±6.89) mmHg] and the decrease of ineffective swallowing [9.15±6.44 vs. 11.25±2.04](both P<0.05), while such results of Dor group were similar to Nissen group[(19.87±10.40) mmHg, 6.15±2.95, all P>0.05]. The GERD Q scores were significantly decreased after operation in 3 groups(Nissen group:10.94±2.20 vs.7.41±1.43, t=11.667, P=0.001; Toupet group: 10.91±2.02 vs.7.18±1.33, t=5.109, P=0.005; Dor group: 10.69±1.69 vs. 7.10±1.30, t=7.610, P=0.002). There was no significant difference in GERD Q scores among three groups (F=1.465, P=0.207). The operative time, blood loss, hospital stay and complications were not significantly different among 3 groups (all P>0.05). Follow-up period was 12-51 months (median 19 months), and no significant difference in recurrence was found [Nissen group: 2 cases (1.3%), Toupet group: 1 case (2.4%), Dor group: 1 case (1.2%), χ2=0.363, P=0.834]. CONCLUSIONS: It is safe and feasible for these three laparoscopic fundoplications to the treatment of hiatal hernia complicated with GERD. But laparoscopic Nissen and Dor fundoplication are better than Toupet fundoplication in reducing the number of reflux episodes, suppressing long reflux, increasing lower esophageal sphincter pressure (mean resting respiration) and decreasing the incidence of postoperative dysphagia.