Landau-phonon polaritons in Dirac heterostructures.

Polaritons are light-matter quasiparticles that govern the optical response of quantum materials at the nanoscale, enabling on-chip communication and local sensing. Here, we report Landau-phonon polaritons (LPPs) in magnetized charge-neutral graphene encapsulated in hexagonal boron nitride (hBN). These quasiparticles emerge from the interaction of Dirac magnetoexciton modes in graphene with the hyperbolic phonon polariton modes in hBN. Using infrared magneto-nanoscopy, we reveal the ability to completely halt the LPP propagation in real space at quantized magnetic fields, defying the conventional optical selection rules. The LPP-based nanoscopy also tells apart two fundamental many-body phenomena: the Fermi velocity renormalization and field-dependent magnetoexciton binding energies. Our results highlight the potential of magnetically tuned Dirac heterostructures for precise nanoscale control and sensing of light-matter interaction.

Effect of patient position on the EEG bispectral index and entropy index under general anaesthesia.

BACKGROUND: Perioperative depth monitoring techniques, such as electroencephalography bispectral index (BIS), entropy index, and auditory evoked potential, are commonly used to assess anesthesia depth. However, the influence of patient positioning changes, particularly in gynecological surgeries where a head-down position is often required, on the accuracy of these monitoring indices remains unexplored. OBJECTIVE: The aim of the our study was to observe the impact of patient position changes on the monitoring value of entropy and BIS to identify a more sensitive method of anaesthesia depth monitoring for gynaecological surgery patients. METHODS: We conducted a study involving 40 women undergoing general anesthesia, during which routine monitoring of vital signs, including electrocardiogram (ECG), heart rate (HR), noninvasive arterial blood pressure (NIBP), oxyhemoglobin saturation (SpO2), and end-expiratory carbon dioxide (PetCO2), was initiated. Entropy and BIS devices were affixed to the patients' foreheads after alcohol sterilization to record brain activity. Tracheal intubation was performed following anesthesia induction. Throughout anesthesia maintenance, the value of BIS and response entropy (RE) were monitored and maintained between 40 and 50 by adjusting the infusion rate of propofol and remifentanil with Target Controlled Infusion (TCI, Mintopharmacokinetics model). Dosing for infusion control utilized corrected weight (height-105). Data were recorded before and after position changes, including tilting the operating table to head-down positions of 15 and 25 degrees, returning to a supine position, and elevating the head to 15 and 25-degree angles. BIS and entropy values at different time points were compared between the groups. RESULTS: Both BIS and entropy values increased from supine to head-down position and decreased from supine to head-up position, with entropy changes preceding those of BIS. Heart rate increased after head-up and decreased after head-down, while mean blood pressure (MBP) exhibited the opposite effect on heart rate. Significant correlations were found between heart rate and BIS (correlation coefficient: -0.43) and RE (correlation coefficient: -0.416), as well as between MBP and BIS (correlation coefficient: 0.346) and RE (correlation coefficient: 0.384). CONCLUSION: Changes in patient position can significantly affect the value of RE and BIS, as changes in entropy occur earlier than changes in the BIS.

Activation of GABAergic neurons in the dorsal raphe nucleus alleviates hyperalgesia induced by ovarian hormone withdrawal.

ABSTRACT: Menopausal and postmenopausal women, characterized by a significant reduction in ovarian hormones, have a high prevalence of chronic pain with great pain intensity. However, the underlying mechanism of hyperalgesia induced by ovarian hormone withdrawal remains poorly understood. Here, we report that decreases in the activity and excitability of GABAergic neurons in the dorsal raphe nucleus (DRN) are associated with hyperalgesia induced by ovariectomy in mice. Supplementation with 17ß-estradiol, but not progesterone, is sufficient to increase the mechanical pain threshold in ovariectomized (OVX) mice and the excitability of DRN GABAergic (DRNGABA) neurons. Moreover, activation of the DRNGABA neurons projecting to the lateral parabrachial nucleus was critical for alleviating hyperalgesia in OVX mice. These findings show the essential role of DRNGABA neurons and their modulation by estrogen in regulating hyperalgesia induced by ovarian hormone withdrawal, providing therapeutic basis for the treatment of chronic pain in physiological or surgical menopausal women.

Association between neutrophil-to-lymphocyte ratio and epidural-related maternal fever in Chinese parturients: a prospective cohort study.

OBJECTIVE: Epidural analgesia could increase the risk of maternal fever during labor, and the potential mechanisms involved inflammation. Neutrophil-to-lymphocyte ratio (NLR) was a sensitive inflammatory composite indicator and related to adverse outcomes in parturients. This study aimed to investigate the association between NLR levels and epidural related maternal fever (ERMF). METHODS: This prospective cohort study included 614 parturients who underwent epidural analgesia at the Women's Hospital School of Medicine Zhejiang University from November 2021 to May 2023. NLR level was calculated before epidural analgesia for women. The outcome was ERMF. Univariate and multivariate logistic regression models were utilized to explore the association between NLR level and ERMF. And the association was further investigated in subgroups of age, body mass index (BMI) before pregnancy, and parity of delivery. The results were presented as odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Totally, 614 parturients, of whom 171 (27.85%) had ERMF. High NLR level was associated with higher incidence of ERMF (OR = 2.70, 95% CI: 1.58-4.69). Parturients with ERMF had higher proportion of postpartum hemorrhage, longer labor times, and other adverse outcomes in parturients. The association also observed in subgroups of age <35 years old (OR = 2.74, 95% CI: 1.55-4.29), BMI <24 kg/m2 before pregnancy (OR = 2.32, 95% CI: 1.32-4.13), BMI ≥24 kg/m2 before pregnancy (OR = 38.28, 95%CI: 3.67-854.66), primipara (OR = 2.26, 95% CI:1.27-4.04), and multipara (OR = 30.60, 95% CI: 3.73-734.03). CONCLUSION: High NLR levels were associated with ERMF in women. It indicated that physicians may measure NLR levels as a regular measurement, which may beneficial for pregnancy outcomes.

Norepinephrine or phenylephrine for the prevention of post-spinal hypotension after caesarean section: A double-blinded, randomized, controlled study of fetal heart rate and fetal cardiac output.

STUDY OBJECTIVE: Spinal anesthesia often causes hypotension, with consequent risk to the fetus. The use of vasopressor agents has been highly recommended for the prevention of spinal anesthesia-induced hypotension during caesarean delivery. Many studies have shown that norepinephrine can provide more stable maternal hemodynamics than phenylephrine. We therefore tested the hypothesis that norepinephrine preserves fetal circulation better than phenylephrine when used to treat maternal hypotension consequent to spinal anesthesia. DESIGN: Prospective, randomized, double-blinded study. SETTING: Operating room. PATIENTS: We recruited 223 parturients with uncomplicated singleton pregnancies who were scheduled for elective caesarean section under combined spinal-epidural anesthesia. INTERVENTIONS: The patients received prophylactic intravenous infusion of either 0.08 µg/kg/min norepinephrine or 0.5 µg/kg/min phenylephrine for prevention of spinal anesthesia-induced hypotension. MEASUREMENTS: Changes in fetal heart rate and fetal cardiac output before and after spinal anesthesia were measured using noninvasive Doppler ultrasound. MAIN RESULTS: 90 subjects who received norepinephrine infusion and 93 subjects who received phenylephrine infusion were ultimately analyzed in the present study. The effects of norepinephrine and phenylephrine on the change of fetal heart rate and fetal cardiac output at 3 and 6 min after spinal block were similar. Although there was a statistically significant decrease in fetal cardiac output at 6 min after subarachnoid block initiation in both the norepinephrine group (mean difference 0.02 L/min; 95% CI, 0-0.04 L/min; P = 0.03) and the phenylephrine group (mean difference 0.02 L/min; 95% CI, 0-0.04 L/min; P = 0.02), it remained within the normal range. CONCLUSIONS: Prophylactic infusion of comparable doses of phenylephrine or norepinephrine has similar effects on fetal heart rate and cardiac output changes after spinal anesthesia. Neither phenylephrine nor norepinephrine has meaningful detrimental effects on fetal circulation or neonatal outcomes.

Intravenous Bolus of Dexmedetomidine for Treatment of Severe Shivering After Caesarean Delivery Under Combined Spinal-Epidural Anaesthesia: A Randomized Dose-Response Study.

Purpose: Shivering occurs frequently after caesarean delivery. The present study aimed to investigate the ED50 and ED95 of an intravenous (i.v.) bolus of dexmedetomidine for treating severe shivering after caesarean delivery under combined spinal-epidural anaesthesia. Patients and methods: Seventy-five parturients with severe shivering after caesarean delivery were randomized into one of the five groups to receive an i.v. bolus of 0.2 (Group D1), 0.25 (Group D2), 0.3 (Group D3), 0.35 (Group D4) or 0.4 (Group D5) µg/kg of dexmedetomidine. Effectiveness of shivering treatment was defined as a standardized shivering score decreasing to ≤1 within 10 min of dexmedetomidine injection. The ED50 and ED95 were determined by probit regression. Adverse effects were also compared among the groups. Results: The ED50 and ED95 of i.v. dexmedetomidine to treat severe shivering were 0.23 (95% CI, 0.16-0.26) µg/kg and 0.39 (95% CI, 0.34-0.52) µg/kg, respectively. No difference in the incidence of adverse effects was found between groups. Conclusion: An i.v. bolus of 0.39 µg/kg of dexmedetomidine will treat 95% of parturients experiencing severe shivering after caesarean delivery.

Randomized Double-Blind Study of the Effect of Injectate Temperature on Intrathecal Bupivacaine Dose Requirement in Spinal Anesthesia for Cesarean Delivery.

BACKGROUND: Increasing the temperature of intrathecal local anesthetics has been shown to increase the speed of onset and block height of spinal anesthesia. However, how this influences dose requirement has not been fully quantified. The aim of this study was to determine and compare the effective dose for anesthesia for cesarean delivery in 50% of patients (ED50) of intrathecal bupivacaine given at temperatures of 37 °C (body temperature) or 24 °C (room temperature). METHODS: Eighty healthy parturients having elective cesarean delivery under combined spinal-epidural anesthesia were randomly assigned to receive intrathecal hyperbaric bupivacaine stored at 37 °C (body temperature group) or 24 °C (room temperature group). The first subject in each group received a bupivacaine dose of 10 mg. The dose for each subsequent subject in each group was varied with an increment or decrement of 1 mg based on the response (effective or noneffective) of the previous subject. Patients for whom the dose was noneffective received epidural supplementation after data collection with lidocaine 2% as required until anesthesia was sufficient for surgery. Values for ED50 were calculated using modified up-down sequential analysis with probit analysis applied as a backup sensitivity analysis. These values were compared and the relative mean potency was calculated. RESULTS: The ED50 (mean [95% confidence interval, CI]) of intrathecal hyperbaric bupivacaine was lower in the body temperature group (6.7 [5.7-7.6] mg) compared with the room temperature group (8.1 [7.7-8.6] mg) (P < .05). The relative potency ratio for intrathecal bupivacaine for the room temperature group versus the body temperature group was 0.84 (95% CI, 0.77-0.93). CONCLUSIONS: Warming hyperbaric bupivacaine to body temperature reduced the dose requirement for spinal anesthesia for cesarean delivery by approximately 16% (95% CI, 7%-23%).

Efficacy of a single low dose of esketamine after childbirth for mothers with symptoms of prenatal depression: randomised clinical trial.

OBJECTIVE: To determine whether a single low dose of esketamine administered after childbirth reduces postpartum depression in mothers with prenatal depression. DESIGN: Randomised, double blind, placebo controlled trial with two parallel arms. SETTING: Five tertiary care hospitals in China, 19 June 2020 to 3 August 2022. PARTICIPANTS: 364 mothers aged ≥18 years who had at least mild prenatal depression as indicated by Edinburgh postnatal depression scale scores of ≥10 (range 0-30, with higher scores indicating worse depression) and who were admitted to hospital for delivery. INTERVENTIONS: Participants were randomly assigned 1:1 to receive either 0.2 mg/kg esketamine or placebo infused intravenously over 40 minutes after childbirth once the umbilical cord had been clamped. MAIN OUTCOME MEASURES: The primary outcome was prevalence of a major depressive episode at 42 days post partum, diagnosed using the mini-international neuropsychiatric interview. Secondary outcomes included the Edinburgh postnatal depression scale score at seven and 42 days post partum and the 17 item Hamilton depression rating scale score at 42 days post partum (range 0-52, with higher scores indicating worse depression). Adverse events were monitored until 24 hours after childbirth. RESULTS: A total of 364 mothers (mean age 31.8 (standard deviation 4.1) years) were enrolled and randomised. At 42 days post partum, a major depressive episode was observed in 6.7% (12/180) of participants in the esketamine group compared with 25.4% (46/181) in the placebo group (relative risk 0.26, 95% confidence interval (CI) 0.14 to 0.48; P<0.001). Edinburgh postnatal depression scale scores were lower in the esketamine group at seven days (median difference -3, 95% CI -4 to -2; P<0.001) and 42 days (-3, -4 to -2; P<0.001). Hamilton depression rating scale scores at 42 days post partum were also lower in the esketamine group (-4, -6 to -3; P<0.001). The overall incidence of neuropsychiatric adverse events was higher in the esketamine group (45.1% (82/182) v 22.0% (40/182); P<0.001); however, symptoms lasted less than a day and none required drug treatment. CONCLUSIONS: For mothers with prenatal depression, a single low dose of esketamine after childbirth decreases major depressive episodes at 42 days post partum by about three quarters. Neuropsychiatric symptoms were more frequent but transient and did not require drug intervention. TRIAL REGISTRATION: ClinicalTrials.gov NCT04414943.

Optimal flow of high-flow nasal cannula oxygenation to prevent desaturation during sedation for bronchoscopy: a randomized controlled study.

BACKGROUND: Although high-flow nasal cannula (HFNC) oxygenation is currently recommended to prevent desaturation during sedation for bronchoscopy, there is no consensus on an optimal flow rate. OBJECTIVE: To determine the optimal oxygen flow rate for HFNC to effectively prevent desaturation during sedation for bronchoscopy. DESIGN: Prospective, randomized, and controlled study. METHODS: Patients (n = 240) scheduled for bronchoscopy were randomized to receive HFNC with propofol sedation (fraction of inspired oxygen, 100%) at one of six flow rates of 10, 20, 30, 40, 50, and 60 L/min, designated as groups 1-6, respectively. RESULTS: The incidence of desaturation significantly decreased by increasing the oxygen flow rate (42.5%, 17.5%, 15%, 10%, 2.5%, and 0% for groups 1-6, respectively, p < 0.0001). The optimal oxygen flow rate for HFNC determined by probit regression to effectively prevent desaturation in 95% of patients was 43.20 (95% confidence interval, 36.43-55.96) L/min. The requirement for airway intervention was significantly decreased by increasing the oxygen flow rate. CONCLUSION: An HFNC flow rate of 50-60 L/min is recommended to prevent desaturation during sedation for bronchoscopy. REGISTRATION: NCT05298319 at ClinicalTrials.gov.

High-flow nasal cannula oxygenation during bronchoscopyMany patients undergo a special test to check their airways for problems. Sometimes, doctors need to take out a small part of the area that's causing trouble to find out what's wrong. But during this test, some patients can struggle to get enough oxygen, which can even be life-threatening. To help with this, there's a device called a high-flow nasal cannula (HFNC). It gives patients adjustable amounts of oxygen, like a gentle breeze into their nose. But doctors weren't sure how much oxygen was best during this test. So, we studied 240 patients using HFNC at different oxygen levels­like slow, medium, and fast flows. We found that the higher the oxygen flow, the less likely patients were to have oxygen problems. For example, at the lowest flow (10 liters per minute), about 42.5% of patients had oxygen trouble, but at the highest flow (60 liters per minute), none did. And we figured out that a flow rate around 43.2 liters per minute would prevent 95% patients from having oxygen problems. So, we recommend using a flow rate between 50 and 60 liters per minute during this test to keep patients safe from oxygen issues.

Ncf1 knockout in smooth muscle cells exacerbates angiotensin II-induced aortic aneurysm and dissection by activating the STING pathway.

AIMS: Aortic aneurysm and dissection (AAD) is caused by the progressive loss of aortic smooth muscle cells (SMCs) and is associated with a high mortality rate. Identifying the mechanisms underlying SMC apoptosis is crucial for preventing AAD. Neutrophil cytoplasmic factor 1 (Ncf1) is essential in reactive oxygen species production and SMC apoptosis; Ncf1 absence leads to autoimmune diseases and chronic inflammation. Here, the role of Ncf1 in angiotensin II (Ang II)-induced AAD was investigated. METHODS AND RESULTS: Ncf1 expression increased in injured SMCs. Bioinformatic analysis identified Ncf1 as a mediator of AAD-associated SMC damage. Ncf1 expression is positively correlated with DNA replication and repair in SMCs of AAD aortas. AAD incidence increased in Ang II-challenged Sm22CreNcf1fl mice. Transcriptomics showed that Ncf1 knockout activated the stimulator of interferon genes (STING) and cell death pathways. The effects of Ncf1 on SMC death and the STING pathway in vitro were examined. Ncf1 regulated the hydrogen peroxide-mediated activation of the STING pathway and inhibited SMC apoptosis. Mechanistically, Ncf1 knockout promoted the ubiquitination of nuclear factor erythroid 2-related factor 2 (NRF2), thereby inhibiting the negative regulatory effect of NRF2 on the stability of STING mRNA and ultimately promoting STING expression. Additionally, the pharmacological inhibition of STING activation prevented AAD progression. CONCLUSION: Ncf1 deficiency in SMCs exacerbated Ang II-induced AAD by promoting NRF2 ubiquitination and degradation and activating the STING pathway. These data suggest that Ncf1 may be a potential therapeutic target for AAD treatment.

Tunable Phonon Polariton Hybridization in a Van der Waals Hetero-Bicrystal.

Phonon polaritons, the hybrid quasiparticles resulting from the coupling of photons and lattice vibrations, have gained significant attention in the field of layered van der Waals heterostructures. Particular interest has been paid to hetero-bicrystals composed of molybdenum oxide (MoO3) and hexagonal boron nitride (hBN), which feature polariton dispersion tailorable via avoided polariton mode crossings. In this work, the polariton eigenmodes in MoO3-hBN hetero-bicrystals self-assembled on ultrasmooth gold are systematically studied using synchrotron infrared nanospectroscopy. It is experimentally demonstrated that the spectral gap in bicrystal dispersion and corresponding regimes of negative refraction can be tuned by material layer thickness, and these results are quantitatively matched with a simple analytic model. Polaritonic cavity modes and polariton propagation along "forbidden" directions are also investigated in microscale bicrystals, which arise from the finite in-plane dimension of the synthesized MoO3 micro-ribbons. The findings shed light on the unique dispersion properties of polaritons in van der Waals heterostructures and pave the way for applications leveraging deeply sub-wavelength mid-infrared light-matter interactions.

Gut microbiota dysbiosis contributes to depression-like behaviors via hippocampal NLRP3-mediated neuroinflammation in a postpartum depression mouse model.

Postpartum depression (PPD) is a severe mental disorder that affects approximately 10---20% of women after childbirth. The precise mechanism underlying PPD pathogenesis remains elusive, thus limiting the development of therapeutics. Gut microbiota dysbiosis is considered to contribute to major depressive disorder. However, the associations between gut microbiota and PPD remain unanswered. Here, we established a mouse PPD model by sudden ovarian steroid withdrawal after hormone-simulated pseudopregnancy-human (HSP-H) in ovariectomy (OVX) mouse. Ovarian hormone withdrawal induced depression-like and anxiety-like behaviors and an altered gut microbiota composition. Fecal microbiota transplantation (FMT) from PPD mice to antibiotic cocktail-treated mice induced depression-like and anxiety-like behaviors and neuropathological changes in the hippocampus of the recipient mice. FMT from healthy mice to PPD mice attenuated the depression-like and anxiety-like behaviors as well as the inflammation mediated by the NOD-like receptor protein (NLRP)-3/caspase-1 signaling pathway both in the gut and the hippocampus, increased fecal short-chain fatty acids (SCFAs) levels and alleviated gut dysbiosis with increased SCFA-producing bacteria and reduced Akkermansia in the PPD mice. Also, downregulation of NLRP3 in the hippocampus mitigated depression-like behaviors in PPD mice and overexpression of NLRP3 in the hippocampal dentate gyrus induced depression-like behaviors in naïve female mice. Intriguingly, FMT from healthy mice failed to alleviate depression-like behaviors in PPD mice with NLRP3 overexpression in the hippocampus. Our results highlighted the NLRP3 inflammasome as a key component within the microbiota-gut-brain axis, suggesting that targeting the gut microbiota may be a therapeutic strategy for PPD.

Off-pump versus on-pump coronary artery bypass grafting in elderly patients at 30 days: a propensity score matching study.

BACKGROUND: Elderly patients are at increased risk of perioperative morbidity and mortality after conventional on-pump coronary artery bypass grafting (ONCABG). This study was to determine whether such high-risk population would benefit from off-pump coronary artery bypass grafting (OPCABG). METHODS: A retrospective analysis was performed on patients aged 65 years or older who underwent isolated coronary artery bypass grafting for the first time in Wuhan Union Hospital from January 2015 to January 2021. We used propensity score matching to adjust for differences in baseline characteristics between the ONCABG and OPCABG groups. Morbidity and mortality within 30 days after surgery were compared between the two groups. All operations were performed by experienced cardiac surgeons. RESULTS: A total of 511 patients (ONCABG 202, OPCABG 309) were included. After 1:1 matching, the baseline characteristics of the two groups were comparable (ONCABG 173, OPCABG 173). The OPCABG group had higher rate of incomplete revascularization (13.9% vs. 6.9%; P = .035) than the ONCABG group. However, OPCABG reduced the risk of postoperative renal insufficiency (15.0% vs. 30.1%; P = .001) and reoperation for bleeding (0.0% vs. 3.5%; P = .030). There were no significant differences in early postoperative mortality, myocardial infarction, stroke, and other outcomes between the two groups. CONCLUSIONS: OPCABG is an alternative revascularization method for elderly patients. It reduces the risk of early postoperative renal insufficiency and reoperation for bleeding.

Effect of Remimazolam Supplementation on Propofol Requirements During Hysteroscopy: A Double-Blind, Dose-Response Study.

BACKGROUND: Propofol is commonly used for procedural sedation but may increase side effects in a dose-dependent manner. Remimazolam, an ultrashort-acting benzodiazepine, has been approved for procedural sedation but may delay awakening. This study tested the hypothesis that remimazolam as a supplement reduces effect-site propofol concentration (Ceprop) required to suppress response to cervical dilation in patients undergoing hysteroscopy. METHODS: One hundred and fifty patients who were scheduled for hysteroscopy were randomized to receive 0, 0.05, 0.1, 0.15, or 0.2 mg·kg-1 intravenous remimazolam, followed by a bolus of sufentanil 0.15 µg⋅kg-1, and a target-controlled propofol infusion. The initial target Ceprop was 3.5 µg·mL-1 and was increased or decreased in subsequent patients by steps of 0.5 µg·mL-1 according to whether there was loss of response to cervical dilation in the previous patient. We used up-down sequential analysis to determine values of Ceprop that suppressed response to cervical dilation in 50% of patients (EC50). RESULTS: The EC50 of propofol for suppressing response to cervical dilation was lower in patients given 0.1 mg·kg-1 (2.08 [95% confidence interval, CI, 1.88-2.28] µg·mL-1), 0.15 mg⋅kg-1 (1.83 [1.56-2.10] µg·mL-1), and 0.2 mg⋅kg-1 (1.43 [1.27-1.58] µg·mL-1) remimazolam than those given 0 mg⋅kg-1 (3.67 [3.49-3.86] µg·mL-1) or 0.05 mg⋅kg-1 (3.47 [3.28-3.67] µg·mL-1) remimazolam (all were P < .005). Remimazolam at doses of 0.1, 0.15, and 0.2 mg·kg-1 decreased EC50 of propofol by 43.3% (95% CI, 41.3%-45.5%), 50.3% (48.0%-52.8%), and 61.2% (58.7%-63.8%), respectively, from baseline (remimazolam 0 mg⋅kg-1). Propofol consumption was lower in patients given 0.1 mg⋅kg-1 (4.15 [3.51-5.44] mg·kg-1), 0.15 mg⋅kg-1 (3.54 [3.16-4.46] mg·kg-1), and 0.2 mg⋅kg-1 (2.74 [1.73-4.01] mg·kg-1) remimazolam than those given 0 mg⋅kg-1 (6.09 [4.99-7.35] mg·kg-1) remimazolam (all were P < .005). Time to anesthesia emergence did not differ significantly among the 5 groups. CONCLUSIONS: For women undergoing hysteroscopic procedures, remimazolam at doses from 0.1 to 0.2 mg·kg-1 reduced the EC50 of propofol inhibiting response to cervical dilation and the total propofol requirement. Whether the combination could improve perioperative outcomes deserves further investigation.

Accelerated Nano-Optical Imaging through Sparse Sampling.

The integration time and signal-to-noise ratio are inextricably linked when performing scanning probe microscopy based on raster scanning. This often yields a large lower bound on the measurement time, for example, in nano-optical imaging experiments performed using a scanning near-field optical microscope (SNOM). Here, we utilize sparse scanning augmented with Gaussian process regression to bypass the time constraint. We apply this approach to image charge-transfer polaritons in graphene residing on ruthenium trichloride (α-RuCl3) and obtain key features such as polariton damping and dispersion. Critically, nano-optical SNOM imaging data obtained via sparse sampling are in good agreement with those extracted from traditional raster scans but require 11 times fewer sampled points. As a result, Gaussian process-aided sparse spiral scans offer a major decrease in scanning time.

Neuron-derived exosomes mediate sevoflurane-induced neurotoxicity in neonatal mice via transferring lncRNA Gas5 and promoting M1 polarization of microglia.

Sevoflurane exposure during rapid brain development induces neuronal apoptosis and causes memory and cognitive deficits in neonatal mice. Exosomes that transfer genetic materials including long non-coding RNAs (lncRNAs) between cells play a critical role in intercellular communication. However, the lncRNAs found in exosomes derived from neurons treated with sevoflurane and their potential role in promoting neurotoxicity remain unknown. In this study, we investigated the role of cross-talk of newborn mouse neurons with microglial cells in sevoflurane-induced neurotoxicity. Mouse hippocampal neuronal HT22 cells were exposed to sevoflurane, and then co-cultured with BV2 microglial cells. We showed that sevoflurane treatment markedly increased the expression of the lncRNA growth arrest-specific 5 (Gas5) in neuron-derived extracellular vesicles, which inhibited neuronal proliferation and induced neuronal apoptosis by promoting M1 polarization of microglia and the release of inflammatory cytokines. We further revealed that the exosomal lncRNA Gas5 significantly upregulated Foxo3 as a competitive endogenous RNA of miR-212-3p in BV2 cells, and activated the NF-κB pathway to promote M1 microglial polarization and the secretion of inflammatory cytokines, thereby exacerbating neuronal damage. In neonatal mice, intracranial injection of the exosomes derived from sevoflurane-treated neurons into the bilateral hippocampi significantly increased the proportion of M1 microglia, inhibited neuronal proliferation and promoted apoptosis, ultimately leading to neurotoxicity. Similar results were observed in vitro in BV2 cells treated with the CM from HT22 cells after sevoflurane exposure. We conclude that sevoflurane induces the transfer of lncRNA Gas5-containing exosomes from neurons, which in turn regulates the M1 polarization of microglia and contributes to neurotoxicity. Thus, modulating the expression of lncRNA Gas5 or the secretion of exosomes could be a strategy for addressing sevoflurane-induced neurotoxicity.

Propofol EC50 for inducing loss of consciousness in patients under combined epidural-general anesthesia or general anesthesia alone: a randomized double-blind study.

Background: Combined epidural-general anesthesia (GA + EA) has been recommended as a preferred technique for both thoracic and abdominal surgery. The epidural anesthesia on the general anesthetic (GA) requirements has not been well investigated. Therefore, we conducted the present study to explore the predicted effect-site concentration of propofol (Ceprop) required for achieving the loss of consciousness (LOC) in 50% of patients (EC50) with or without epidural anesthesia. Methods: Sixty patients scheduled for gastrectomy were randomized into the GA + EA group or GA alone group to receive general anesthesia alone. Ropivacaine 0.375% was used for epidural anesthesia to achieve a sensory level of T4 or above prior to the induction of general anesthesia. The EC50 of predicted Ceprop for LOC was determined by the up-down sequential method. The consumption of anesthetics, emergence time from anesthesia, and postoperative outcomes were also recorded and compared. Results: The EC50 of predicted Ceprop for LOC was lower in the GA + EA group than in the GA alone group [2.97 (95% CI: 2.63-3.31) vs. 3.36 (95% CI: 3.19-3.53) µg mL-1, (p = 0.036)]. The consumption of anesthetics was lower in the GA + EA group than in the GA alone group (propofol: 0.11 ± 0.02 vs. 0.13 ± 0.02 mg kg-1 min-1, p = 0.014; remifentanil: 0.08 ± 0.03 vs. 0.14 ± 0.04 µg kg-1 min-1, p < 0.001). The emergence time was shorter in the GA + EA group than in the GA alone group (16.0 vs. 20.5 min, p = 0.013). Conclusion: Concomitant epidural anesthesia reduced by 15% the EC50 of predicted Ceprop for LOC, decreased the consumptions of propofol and remifentanil during maintenance of anesthesia, and fastened recovery from anesthesia. Clinical trial registration: ClinicalTrials.gov, identifier: NCT05124704.