Transcutaneous Electrical Acupoint Stimulation Improves Postoperative Sleep Quality in Patients Undergoing Laparoscopic Gastrointestinal Tumor Surgery: A Prospective, Randomized Controlled Trial.

INTRODUCTION: This study was conducted to observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on the postoperative sleep quality of patients undergoing gastrointestinal tumor surgery and to verify the possible mechanism. METHODS: Eighty-three patients were allocated to the TEAS or Sham group. Patients in the TEAS group received TEAS treatment (disperse-dense waves; frequency, 2/100 Hz) on bilateral Shenmen (HT7), Neiguan (PC6) and Zusanli (ST36) points for 30 min each time, total three times in the perioperative period. In the Sham group, electrodes were placed; however, no current was given. Sleep quality was assessed on the day before surgery (P1) and the first and third days after surgery (D1 and D3) using the Pittsburgh Sleep Quality Index (PSQI) and Athens Insomnia Scale (AIS). Postoperative pain was assessed using visual analog scale (VAS) 72 h postoperatively. The incidences of abdominal distension, dizziness, postoperative nausea and vomiting (PONV) and pulmonary complications were recorded. Serum levels of inflammatory cytokines and the expression of key factors of oxidative stress and key molecules of the nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) signal pathway were measured. RESULTS: TEAS ameliorated sleep quality at D1 and D3 (PSQI P < 0.05, AIS P < 0.05) and decreased postoperative pain as demonstrated by lower VAS scores compared to the Sham group (P < 0.05). The incidences of abdominal distension and PONV were also lower in the TEAS group. Markers of oxidative stress were increased (P < 0.05), and the serum concentration of interleukin-6 (IL-6) was significantly lower in the TEAS group. The key mediators of the Nrf2/ARE pathway were enhanced after TEAS. CONCLUSION: Perioperative TEAS improved postoperative sleep quality, reduced postoperative pain and alleviated postoperative adverse effects in patients undergoing laparoscopic gastrointestinal tumor surgery resection. This may be associated with activating Nrf2/ARE signal pathway and decreasing its inflammatory actions. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( http://www.chictr.org.cn/index.aspx ), ChiCTR2100054971.

Self-growth Ni2P nanosheet arrays with cationic vacancy defects as a highly efficient bifunctional electrocatalyst for overall water splitting.

HYPOTHESIS: The transition metal phosphide is one of the promising bifunctional electrocatalysts for overall water splitting. Moreover, the activity of phosphide catalysts can be further enhanced by the cationic vacancy engineering. EXPERIMENTS: The self-growth Ni2P nanosheet arrays with abundant cationic vacancy defects (V-Ni2P/NF) has been synthesized via a facile multi-step reaction process involving hydrothermal, phosphorization and acid-etching of Mn which was doped in Ni2P nanosheets as a sacrificial dopant. Furthermore, the experimental studies and density functional theory (DFT) calculations were carried out to evaluate its electrochemical performance. FINDINGS: The chemical and electrocatalytic property of Ni2P were successfully optimized by cationic vacancy engineering and the obtained V-Ni2P/NF catalyst exhibited superior bifunctional catalytic performance for both hydrogen evolution (HER) and oxygen evolution reaction (OER) compared to pristine Ni2P and Mn-doped Ni2P in alkaline electrolyte. The V-Ni2P/NF can afford the current density of 10 mA cm-2 at a small overpotential of 55 mV for HER and 250 mV for OER. Additionally, the water electrolysis device assembled by the V-Ni2P/NF electrode as both the anode and cathode just requires a small voltage of 1.59 V to achieve 10 mA cm-2 and shows no obvious attenuation for 50 h.

11-watt single-frequency 1342-nm laser based on multi-segmented Nd:YVO4 crystal.

High power continuous-wave (CW) single-frequency 1342 nm lasers are of interest for fundamental research, particularly, for laser cooling of lithium atoms. Using the popular Nd:YVO4 laser crystal requires careful heat management, because strong thermal effects in the gain medium are the most severe limitations of output power. Here, we present a multi-segmented Nd:YVO4 crystal design that consists of three segments with successive doping concentrations, optimized using a theoretical model. In order to quantify the optimization, we measured the thermal lens power of conventional crystal designs and compare them to our multi-segmented design. The optimized design displays a two times lower thermal lens dioptric power for the same amount of absorbed pump power in the non-lasing case. Using the optimized design, we demonstrate a high power all-solid-state laser emitting 10.0 W single-frequency radiation at 1342 nm when operating the laser crystal at room temperature. Further integration of the laser allows us to operate the laser crystal below room temperature for improving output power up to 11.4 W at 8°C. This is explained by the reduction of energy-transfer upconversion and excited-state absorption effects. Stable free-running operation at the low temperature of 8 °C is achieved with the power stability of ± 0.42 % by peak-to-peak fluctuation and frequency peak-to-peak fluctuation of ± 72 MHz in three hours.

High-power 671 nm laser by second-harmonic generation with 93% efficiency in an external ring cavity.

Second-harmonic generation (SHG) is useful for obtaining single-frequency continuous-wave laser sources at various wavelengths for applications ranging from biology to fundamental physics. Using an external power-enhancement cavity is an effective approach to improve the frequency conversion efficiency. However, thermal effects limit the efficiency, particularly, in high-power operation. Therefore, reducing thermal effects is important when designing a cavity. This Letter reports the use of an external ring cavity for SHG, yielding a 5.2 W, 671 nm laser light with a conversion efficiency of 93.8±0.8% which, to the best of our knowledge, is a new record of conversion efficiency for an external ring cavity. It is achieved using a 10 mm length periodically poled potassium titanyl phosphate crystal and a 65 µm radius beam waist in the cavity so as to minimize thermal dephasing and thermal lensing. Furthermore, a method is developed to determine a conversion efficiency more accurately based on measuring the pump depletion using a photodiode detector and a maximum pump depletion up to 97% is recorded. In this method, the uncertainty is much less than that achieved in a common method by direct measuring with a power meter.

Nonlinear spectroscopy of cold atoms in diffuse laser light.

The nonlinear spectroscopy of cold atoms in the diffuse laser cooling system is studied in this paper. We present the theoretical models of the recoil-induced resonances (RIR) and the electromagnetically-induced absorption (EIA) of cold atoms in diffuse laser light, and show their signals in an experiment of cooling (87)Rb atomic vapor in an integrating sphere. The theoretical results are in good agreement with the experimental ones when the light intensity distribution in the integrating sphere is considered. The differences between nonlinear spectra of cold atoms in the diffuse laser light and in the optical molasses are also discussed.