The ability to localize sound sources rapidly allows human beings to efficiently understand the surrounding environment. Previous studies have suggested that there is an auditory "where" pathway in the cortex for processing sound locations. The neural activation in regions along this pathway encodes sound locations by opponent hemifield coding, in which each unilateral region is activated by sounds coming from the contralateral hemifield. However, it is still unclear how these regions interact with each other to form a unified representation of the auditory space. In the present study, we investigated whether functional connectivity in the auditory "where" pathway encoded sound locations during passive listening. Participants underwent functional magnetic resonance imaging while passively listening to sounds from five distinct horizontal locations (-90°, -45°, 0°, 45°, 90°). We were able to decode sound locations from the functional connectivity patterns of the "where" pathway. Furthermore, we found that such neural representation of sound locations was primarily based on the coding of sound lateralization angles to the frontal midline. In addition, whole-brain analysis indicated that functional connectivity between occipital regions and the primary auditory cortex also encoded sound locations by lateralization angles. Overall, our results reveal a lateralization-angle-based representation of sound locations encoded by functional connectivity patterns, which could add on the activation-based opponent hemifield coding to provide a more precise representation of the auditory space.
Humans ; Sound Localization/physiology* ; Male ; Female ; Magnetic Resonance Imaging ; Young Adult ; Functional Laterality/physiology* ; Adult ; Brain Mapping ; Auditory Cortex/physiology* ; Acoustic Stimulation ; Auditory Pathways/physiology* ; Brain/physiology*

Objective:To explore the effect of spontaneous breathing during induction of general anesthesia on atelectasis in patients undergoing laparoscopic resection of gastrointestinal tumors.Methods:A total of 60 patients aged 18-60 years scheduled for laparoscopic resection of gastrointestinal tumors under general anesthesia in the First Hospital of Shanxi Medical University from October 2021 to August 2022 were selected. The body mass index was 18.5-28.0 kg/m 2 and the American Society of Anesthesiology grade wasⅠ-Ⅱ. All patients were divided into the spontaneous breathing group (group S, 30 cases) and the controlled breathing group (group C, 30 cases) according to the random number table method. Patients in group S received 0.2-0.3 mg/kg etomidate (pumping at the speed of 200 ml/h) and 2 μg/kg remifentanil (slowly injected more than 30 s) for anesthesia induction; patients in group C received 0.2-0.3 mg/kg etomidate and 2 μg/kg remifentanil (slowly injected more than 30 s) and 0.2 mg/kg cisatracurium. After bispectral index (BIS) decreased to 80, the patients had no response to the language stimulation; and then the mask was used to closely fit the face and maintain spontaneous breathing in group S; patients in group C received manual positive pressure ventilation. Atelectasis scores were collected immediately after endotracheal intubation (T 1) and 15 min after transferring to the recovery room (T 3), and oxygenation index (OI) was collected 5 min after endotracheal intubation (T 2) and at T 3. The postoperative pulmonary complication (PPC) on the 3rd day after the operation was recorded. Results:A total of 56 patients were finally enrolled, 27 cases in group S and 29 cases in groups C. Compared with group C, the atelectasis score of group S at T 1 and T 3 decreased [T 1: (2.4±0.8) scores vs. (4.2±0.7) scores, t = -9.12, P < 0.001; T 3: (8.2±1.8) scores vs. (10.5±1.6) scores, t = -4.96, P < 0.001]. The OI increased at T 2 and T 3 in group S [T 2: (334±11) mmHg (1 mmHg = 0.133 kPa) vs. (323±13) mmHg, t = 3.45, P = 0.001; T 3: (362±23) mmHg vs. (347±25) mmHg, t = 2.31, P = 0.025]. The incidence of PPC was 20.7% (6/29) and 18.5% (5/27), respectively in group C and group S on the 3rd day after the operation, and the difference was statistically significant ( χ2 = 0.04, P = 0.838). Conclusions:Maintaining spontaneous breathing during induction of general anesthesia can reduce atelectasis caused by general anesthesia and improve oxygenation for patients undergoing laparoscopic resection of gastrointestinal tumors.

Objective:To evaluate the effect of continuous positive airway pressure (CPAP) ventilation during induction of anesthesia on perioperative atelectasis and oxygenation in elderly patients.Methods:Forty-six elderly patients of either sex, aged 65-80 yr, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, undergoing elective cerebrovascular intervention surgery under general anesthesia, were divided into 2 groups ( n=23 each) according to the random number table method: control group (group C) and CPAP ventilation group (group CPAP). During induction of anesthesia, CPAP was set at 5 cmH 2O during spontaneous breathing, and PEEP was set at 5 cmH 2O when spontaneous breathing disappeared, and the ventilation mode was changed to pressure-controlled ventilation (PCV) mode in group CPAP. CPAP was not set, and PEEP was set at 0 cmH 2O for PCV when spontaneous breathing disappeared in group C. During anesthesia maintenance, PCV-volume guaranteed mode was used in both groups, and PEEP was set at 5 cmH 2O. Whole lung CT scanning was performed immediately after radial artery catheterization (T 0), at 1 min after endotracheal intubation (T 1), and before tracheal extubation (T 2) at the end of operation to calculate the percentage of atelectasis area at 1 cm above the right diaphragm. At T 0, T 1, T 2 and 30 min after entering postanesthesia care unit (T 3), blood samples from the radial artery were taken to record PaO 2 and PaCO 2 and calculate the oxygenation index (OI). Results:Compared with the baseline at T 0, the percentage of atelectasis area was significantly increased at T 1 and T 2 in two groups ( P<0.05); PaO 2 was significantly increased at T 1 and T 2 and decreased to T 0 level at T 3, OI was decreased at T 1 and T 2 and increased to T 0 level at T 3 in two groups ( P<0.05). Compared with group C, the percentage of atelectasis area was significantly decreased and PaO 2 and OI were increased at T 1 and T 2 in group CPAP ( P<0.05). There was no significant difference in PaCO 2 at each time point between the two groups ( P>0.05). Conclusions:CPAP ventilation during induction of anesthesia can reduce the development of perioperative atelectasis and improve the oxygenation in elderly patients.

Objective:To evaluate the effect of continuous positive airway pressure(CPAP) ventilation strategy during induction of general anesthesia on atelectasis after induction in obese patients.Methods:A total of 86 patients, aged 30-60 yr, with body mass index of 28-35 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅱor Ⅲ, scheduled for elective cerebrovascular intervention under general anesthesia, were divided into 2 groups ( n=43 each) using a random number table method: CPAP group (group C) and routine group (group R). Group C received CPAP 5 cmH 2O-assisted ventilation after preoxygenation for spontaneous breathing and disappearance of spontaneous breathing. Chest CT scan and arterial blood gas analysis were performed after entering the operating room (T 1) and 5 min after endotracheal intubation (T 2) to calculate the percentage of atelectasis area and to record PaO 2. Dynamic lung compliance and plateau pressure were recorded at T 2. Mean minute ventilation under controlled breathing, P ETCO 2, and use of vasoactive drugs during induction were recorded. The occurrence of reflux and aspiration during mask ventilation was recorded. The development of pulmonary complications within 3 days after operation was recorded. Results:Compared with group R, the percentage of atelectasis area at T 2 was significantly decreased, PaO 2, dynamic lung compliance and plateau pressure were increased ( P<0.05), and no significant change was found in mean minute ventilation, P ETCO 2, requirement for vasoactive drugs and incidence of pulmonary complications in group C ( P>0.05). No reflux or aspiration was observed during mask ventilation. Conclusions:CPAP (5 cmH 2O) strategy during anesthesia induction can reduce the degree of atelectasis after induction in obese patients.

OBJECTIVE:To study the percutaneous absorption of 0.03% Tacrolimus ointment,and to compare the difference of domestic test preparation and imported reference preparation. METHODS:Modified Franz diffusion cells were adopted in trans-dermal test in vitro;HPLC-MS method was used to determine permeation amount and rate in vitro,delay time of domestic test preparation and imported reference preparation 0.03%Tacrolimus ointment. RESULTS:24 h in vitro permeation amount of test and reference preparations were(3 907±1 191)and(3 896±1 064)ng/cm2;permeation rates were 186.7 and 182.9 ng/(cm2·h);de-lay time were 1.95 and 2.00 h,respectively(P>0.05). CONCLUSIONS:Test preparation shows good percutaneous property,and is similar to reference preparation in penetration absorbency through nude mice skin.