Search

The intraoperative effects of mechanical ventilation with individualized positive end-expiratory pressure guided by dynamic compliance on right heart function remains undefined.To investigate whether individualized ventilation is superior to standard ventilation in protecting the right heart during abdominal laparoscopic surgery in the Trendelenburg position.Forty patients who underwent abdominal laparoscopic surgery were randomly divided into two groups: Group T (titrimetric positive end-expiratory pressure [PEEP]) and Group I (intentional PEEP, 5 cmHNo significant difference in the tricuspid annular plane systolic excursion or early-to-late filling ratio of the right ventricle was noted between the groups during the whole procedure (P0.05). We noticed an increase in right ventricular end-diastolic area/left ventricular end-diastolic area ratio at TIntraoperative lung-protective ventilation with dynamic compliance-guided PEEP does not have obvious side effects on the right heart function when compared with standard protective ventilation during laparoscopic surgery in the Trendelenburg position.

General anesthesia might disrupt neuronal network communications measured by functional connectivity (FC; undirected connectivity) and directional information flow (directed connectivity). We sought to characterize the state-dependent effects of propofol on cortico-cortical undirected and directed FC.We collected 256-channel high-density EEGs from 14 patients undergoing surgery while awake (AWA) or in propofol-induced moderate sedation (SED) or loss of consciousness (LOC) states. Using source-space EEG, we estimated neuronal oscillatory activity for 68 cortical regions of interest. FC was analyzed using the weighted phase lag index. Directed connectivity was computed using directed phase transfer entropy (dPTE) as a measure of information flow in the bilateral prefrontal, frontal, parietal, and occipital areas.FC strength evidently reduced during LOC compared with those during the AWA and SED states. The dPTE analysis showed significant propofol-induced changes in directed connectivity. In the alpha band, the prefrontal-to-frontal information flow was significantly stronger in the AWA than in the SED (p = 0.033) and LOC states (p = 0.033). The parietal-to-frontal dPTE was significantly weaker during LOC than during the AWA (p = 0.033) and SED states (p = 0.007). Finally, a loss of occipital-to-frontal connectivity occurred during LOC but not the AWA state (p = 0.001). In the beta band, the dominant occipital-to-frontal direction of information flow in the AWA state was gradually converted to a frontal-to-occipital direction during LOC.Propofol-induced unconsciousness is marked by a decrease in FC and posterior-to-anterior (feedforward) directed connectivity, which may be useful as a measure to discriminate different conscious states caused by propofol administration.The study demonstrates that propofol produces state-dependent effects on cortico-cortical undirected and directed FC, supporting the idea that propofol induces loss of consciousness may through disrupting network interactions and cortical coordination.

Graphene-based metal-free aerogel is desirable for lightweight electromagnetic wave (EMW) absorbing materials. However, the weak van-der-Waals combination between graphene sheets, accompanied by the repulsion from surface oxygen-related polar groups, significantly hinder the transfer of electrons between the sheets, and lead to poor mechanical strength. These become bottlenecks for the further improvement of EMW absorption and have a huge impact on achieving multi-functions. Here, we used an iodine modification strategy to fabricate reduced graphene oxide (RGO) aerogel, in which graphene sheets are bridged by iodine cations (I+). Meanwhile, iodine promotes the conversion of epoxy groups to hydroxyl groups on graphene, thereby facilitating the adhension of I+ on the surface. These iodine cations rather than iodine anions are essential to strengthen the interconnection between graphene sheets, which enables the RGO aerogel to exhibit higher electrical conductivity, larger mechanical strength, higher thermal stability, and significantly improved EMW absorbing capability. With the improvement in conduction loss and impedance matching, the iodine-bridged RGO aerogel exhibits a maximium reflection loss of −52.8 dB and an effective absorption bandwidth of 7.2 GHz at 2 wt% filler loading, which are 3.8 and 1.5 times of pure RGO, respectively. Besides, the improved mechanical strength and resistance to temperature change benefit expanding the application fields of this aerogel.

Plastic polyethylene mulch has been widely used in crop production, but also causes environmental pollution if plastic residues accumulate in soil. Biodegradable plastic mulches (BDM) are a potential solution to problems caused by polyethylene mulches, as BDMs are designed be tilled into the soil after the growing season and then biodegrade. However, the agronomic performance of BDMs still needs to be tested for comparison to polyethylene mulch. We carried out a two-year field experiment in 2018 and 2019 in a typical humid continental climate in Northeast China. Maize was planted in a ridge-furrow pattern, with mulching treatments consisting of no mulch (control), clear BDM, black BDM, clear polyethylene, and black polyethylene. Clear mulches increased soil temperature when compared to no mulch control treatments, while black mulches decreased or did not change soil temperature during the early growing season. Soil temperature and root morphology were similar between BDM and polyethylene mulches for a given type of plastic color. Maize yield did not differ across all the treatments. Maize protein, fat, N and P contents were generally higher for black BDM than other treatments, suggesting that maize quality benefited especially from black BDM. Overall, these results show that, in a humid continental climate, the agronomic performance of clear and black BDMs was equivalent to, or better than, that of polyethylene plastic mulches for maize production.

Hydrogen is widely considered to be the ultimate energy source and has received significant attention from research institutions. Compressors are widely used as the core device for increasing the volumetric energy density of hydrogen. However, conventional reciprocating compressors have problems, such as complex structure, frequent breakdown and large impact. This paper proposes a liquid piston compressor for hydrogen compression. Firstly, the structure and working principle of the compressor are introduced. The compressor adopts a five-stage compression structure, which is driven by a five-piston radial piston pump, and the corresponding hydraulic control system is designed. Secondly, to reduce the return shock of the compressor, the buffer structure is designed for each stage of compression, and theoretical analysis is performed to obtain the theoretical output flow rate of the compressor and the kinematic characteristics of the inlet and discharge processes. Finally, combined with the AMEsim software, the motion of the compressor piston and the characteristics of pressure change during the entire working process in the compressor are simulated. Results show that the novel multi-stage compressor can achieve stable and continuous hydrogen compression, and the buffer structure of each stage greatly reduces the piston impact on the compressor. Compared with the traditional liquid piston compressor, the proposed compressor solves the problems of unstable operation and reduced compression efficiency caused by leakage and reduces the impact and vibration of the piston and increases the stability and controllability of the compressor operation. The analysis results show that the solution is feasible.

The purpose of the present study was to investigate whether methylene blue (MB) could reduce the incidences of postoperative delirium (POD) and early postoperative cognitive dysfunction (POCD) in elderly patients undergoing major non-cardiac surgery.Prospective, randomized, open-label clinical trial.University-affiliated hospital.Two hundred and forty-eight elderly patients scheduled for non-cardiac surgery.Elderly patients undergoing non-cardiac major surgery were randomly assigned to MB group (n = 124), who receiving intravenous infusion of 2 mg/kg MB within 60 min immediately after anesthetic induction, or control group (n = 124), who receiving equal volume saline in the same way.All patients were evaluated with delirium and neuropsychological batteries before and after surgery, as well as perioperative adverse events. Two plasma biomarkers superoxide dismutase (SOD) and homocysteine (HCY) were measured pre- and post-operatively.There were total 39 cases(15.7%)experienced POD. The incidence of POD in MB group was significantly less than that in control group (7.3% vs. 24.2%, OR = 0.24, 95%CI: 0.11-0.53, p 0.001). The incidence of early POCD at postoperative 7th day in MB group was also less than that in control group (16.1% vs. 40.2%, OR = 0.30, 95% CI: 0.16-0.57, p 0.001). The adverse events were comparable in both groups. In addition, there was no significant correlation between POD/POCD and levels of SOD or HCY.We conclude that intraoperative intravenous 2 mg/kg MB could significantly reduce the incidences of POD and early POCD in elderly surgical patients, while not remarkably increase incidence of perioperative adverse events, suggesting MB may be clinically effective and safe for prevention of early postoperative neurocognitive disorders.

Objective In our prior study, we showed that delta-opioid peptide [D-Ala 2 , D-Leu 5 ] enkephalin (DADLE), by regional perfusion into the abdominal aorta, could protect the spinal cord against ischemia-reperfusion (I/R) injury caused by aortic occlusion. However, the relative dose-response effects of DADLE still remain unclear. This study investigated whether DADLE has a dose-dependent efficiency on spinal cord I/R injury. Methods New Zealand White rabbits were randomly divided into one of six groups: normal saline (NS; n = 8), DADLE (D) groups D0.0005 (n = 8), D0.005 (n = 8), D0.05 (n = 8), and D0.5 mg/kg (n = 8), and a sham group (n = 6). In the NS and DADLE groups, spinal cord ischemia was induced by infrarenal aortic occlusion for 30 minutes. During the occlusion, the same volume of NS or DADLE at the indicated doses was infused continuously through a catheter to the distally clamped abdominal aorta. Heart rate, blood pressure, and core temperature were monitored continuously to evaluate the potential adverse effects of DADLE. Neurologic behavioral function was assessed with the Tarlov scale system at 1, 6, 24, 48, and 72 hours after reperfusion. Neuronal injury evaluation in the ventral horn of the gray matter was evaluated by counting the normal motor neurons at 72 hours after reperfusion. Results The therapeutic benefits increased at the doses of DADLE from 0.0005 to 0.05 mg/kg and decreased at 0.5 mg/kg, whereas the hemodynamic parameter was suppressed temporarily at the dose of 0.5 mg/kg. Conclusions These data revealed that regional administration of DADLE through the abdominal aorta provided dose-dependent protection on spinal cord I/R in rabbits.

Background Intracellular calcium overload is a major contributing factor to diaphragmatic dysfunction triggered by sepsis. In this study, the possible role of dantrolene, a ryanodine receptor inhibitor, in preventing the release of calcium from the sarcoplasmic reticulum in diaphragmatic dysfunction and weakness was explored. Methods A middle-grade severity sepsis rat model was established for the effects of treatment with dantrolene, on diaphragm harvested 24 h after cecal ligation and puncture (CLP), and analyzed using functional, histologic, and biomarker assays. Results It was found that in septic rats, treatment with dantrolene significantly improved the contractility, relaxation, and fatigue index of the diaphragm in a dose-dependent manner. The benefits are associated with improvement in ultrastructural changes of Z band integrity and myofilament arrangements along with increases both in the ratio of slow-twitch type composition. Moreover, dantrolene effectively inhibits the overexpression of high-mobility group box 1 and reduces the calpain-1-caspase-3 proteolytic activity. Conclusions Dantrolene can effectively attenuate the dysfunction of diaphragm in septic rats; Furthermore, the beneficial effects were associated with downregulation of high-mobility group box 1 and calpain-1-caspase-3 proteolytic activity.

Background High mobility group box-1 (HMGB1) acts as an inflammatory mediator and has been implicated in pathophysiological damage of vascular inflammatory diseases. Ketamine, an anesthetic agent with sedative and analgesic properties, has been shown to have potent anti-inflammatory effects in a variety of models of systemic inflammation. However, the effects of ketamine on HMGB1-mediated proinflammatory responses have not been fully investigated. In the present study, we investigated the effects of ketamine on HMGB1-activated endothelial cells and explored the underlying mechanisms. Methods Human endothelial cells were incubated with or without HMGB1 (1 μg/mL) in the presence or absence of ketamine, an nuclear factor (NF)-κB inhibitor (PDTC), anti–toll-like receptor (TLR)2/4 antibody, or small interfering RNA (siRNA). The anti-inflammatory activities of ketamine were determined by measuring solute flux, leukocyte adhesion and migration, and activation of proinflammatory proteins in HMGB1-activated endothelial cells. The effect of ketamine on TLR-2/4 and NF-κB activation was evaluated using enzyme-linked immunosorbent assays and immunofluorescence confocal microscopy assay. Results We found that ketamine inhibited the HMGB1-mediated barrier disruption, neutrophil adhesion and migration, and expression of cell adhesion molecules in a dose-dependent manner. Furthermore, ketamine downregulated the TLR-2 and -4, expression in HMGB1-activated endothelial cells. Treatment with ketamine also significantly inhibited the activation of TLR2/4 and the nuclear translocation of NF-κB p50/p65. Furthermore, our study shows that the HMGB1-induced release of inflammatory mediators was suppressed by PDTC, anti-TLR2/4 antibody, and siRNA. Conclusions Our study has demonstrated that ketamine exerts anti-inflammatory effects in HMGB1-mediated proinflammatory responses in a dose-dependent manner. The mechanism responsible for these effects involves the TLR2/4 and NF-κB signaling pathway.

A thieno[3,2-b]thiophene-functionalized porphyrin molecule (DEP-TT) with the ethynylene bridges between the diketopyrrolopyrrole and porphyrin units has been designed and synthesized as the donor material. DEP-TT exhibits a broad absorption wavelength in the visible region with the onset absorption to 898 nm of the film and a low optical band gap of 1.38 eV. IDT-C8, as the acceptor material has a relatively strong absorption spectrum ranging from 500 to 750 nm in the solid film, which exactly fills the absorption trough of DEP-TT. The power conversion efficiency (PCE) of all small molecule increased from 0.64% (Jsc = 2.61 mA cm−2, Voc = 0.82 V, and FF = 0.30) to 5.14% (Jsc = 11.15 mA cm−2, Voc = 0.71 V, and FF = 0.65) after solvent vapor annealing. The PCE of 5.14% provided valuable recommendation based on porphyrin all small molecule system, since few work has involved in this field.

Background T help 2 (Th2) cell differentiation by morphine has been verified. However, the underlying mechanism of morphine induces Th2 cell differentiation remains elusive. The aim of the present study was to explore the possible basis of morphine induced Th2 cell differentiation. Methods Flow cytometry analysis was used to detect the content of T help 1(Th1) cell and Th2 cell. Enzyme linked immunosorbent assay (ELISA) was performed to determine the levels of IL-4 and IFN-γ. Real-time quantitative polymerase chain reaction, electrophoretic mobility shift assay and Western blotting was conducted in this study. Results Th2 cell subset and IL-4 level were elevated in morphine induced naive T cells. Pathway determining found the protein phosphorylation level of PKC-θ and the expression and activity of the transcription factor GATA3 was also enhanced in the naive T cells challenged by morphine. Moreover, inhibitor of morphine(naltrexone) or PKC-θ(AEB071) can reverse morphine-induced Th2 cell differentiation. Conclusion These results suggested that morphine induce naive T cell differentiation to Th2 cells via the PKC-θ/GATA3 signal pathway.

The phase equilibria at 950 °C of the Co–Mo–Ti system was investigated by a combination of a diffusion couple technique and equilibrated alloys. The samples were examined by means of optical microscopy, scanning electron microscopy, electron probe microanalysis, and X-ray diffraction analysis. The isothermal section of the Co–Mo–Ti system at 950 °C consists of 7 three-phase fields and 15 two-phase fields. The following five three-phase equilibria were well determined: (1) TiCo2 (h) + MoCo3 + Mo6Co7, (2) TiCo2 (c) + TiCo2 (h) + TiCo, (3) TiCo2 (h) + TiCo + Mo6Co7, (4) TiCo + Ti2Co + (Mo,Ti), and (5) TiCo + Mo6Co7 + (Mo,Ti). The solubility of Ti in Mo6Co7 was determined to be 23.1 at.% Ti. The solubilities of Mo in TiCo2 (h), TiCo2 (c), and TiCo were measured to be 11.4, 4.7, and 5.4 at.% Mo, respectively. The solubility of Mo in Ti2Co is about 0.3 at.% Mo. The two-phase region of TiCo3 + MoCo3 was found to be very narrow and close to the TiCo3 side.

The phase equilibria of the Co–Ni–Ta system at 1100 °C are investigated using diffusion couples and five equilibrated alloys. The samples are examined by means of optical microscopy, scanning electron microscopy, and electron probe microanalysis. The experimental results show no existence of ternary compounds at 1100 °C. The following 4 three-phase equilibria are observed: (1) Ta(Co, Ni) + β-TaCo 2 + TaNi 3 ; (2) Ta(Co, Ni) + TaNi 2 + TaNi 3 ; (3) β-TaCo 2 + TaNi 3 + (Co, Ni); and (4) TaNi 3 + TaNi 8 + (Co, Ni). The compounds Ta 2 Co and Ta 2 Ni form continuous solid solutions. It is also the case for TaCo and TaNi. The solubilities of Co in TaNi 3 , and Ni in β-TaCo 2 were determined to be up to 70 at.% Co and 30 at.% Ni, respectively.

The isothermal section at 950 °C of the Co–Nb–Ti system was investigated using diffusion couples and six ternary alloys. The specimens were examined by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. No ternary compound was found. Nine three-phase equilibria were observed. The binary intermediate phases NbCo 3 and Nb 2 Co 7 , the existence of which is still controversial in the literature, were observed at 950 °C. The solubilities of Ti in Nb 2 Co 7 , NbCo 3 , λ-NbCo 2 and μ-Nb 6 Co 7 were determined to be 1.9, 16.4, 14.4 and 17.4 at.%, respectively. The solubilities of Nb in TiCo 3 , TiCo 2 (h), TiCo 2 (c), TiCo and Ti 2 Co were determined to be about 5.7, 11.0, 2.6, 13.6 and 3.1 at.%, respectively.