Gas-Dependent Active Sites on Cu/ZnO Clusters for CH3OH Synthesis.

This study describes an instantaneously gas-induced dynamic transition of an industrial Cu/ZnO/Al2O3 catalyst. Cu/ZnO clusters become "alive" and lead to a promotion in reaction rate by almost one magnitude, in response to the variation of the reactant components. The promotional changes are functions of either CO2-to-CO or H2O-to-H2 ratio which determines the oxygen chemical potential thus drives Cu/ZnO clusters to undergo reconstruction and allows the maximum formation of Cu-Zn2+ sites for CH3OH synthesis.

Initiating Continuous Renal Replacement Therapy in Patients With Transurethral Resection of Prostate Syndrome: A Case Report.

With advances and developments in hysteroscopy, cystoscopy, transurethral resection of bladder tumor, and arthroscopy, transurethral resection of prostate (TURP) syndrome has been increasingly reported. TURP syndrome is often accompanied by severe hyponatremia, fluid overload, and a plasma hypotonic state, resulting in heart failure and pulmonary and cerebral edema. Conventional treatment methods, such as intravenous infusion of hyperosmotic saline, can rapidly reverse the downward trend of serum sodium levels in efforts to prevent and treat cerebral edema. However, this may not be suitable for patients with cardiac and renal insufficiency and may induce central pontine myelinolysis due to the possibility of worsening volume load and difficulty in controlling the correction rate of serum sodium. The patient described in this report presented with severe hyponatremia (sodium<100 mmol/L) combined with intraoperative pulmonary edema; his cardiac function and oxygenation status deteriorated after an intravenous infusion of 3% hypertonic saline. He underwent continuous renal replacement therapy (CRRT) to prevent the progression of multiple-organ edema and cardiac insufficiency. CRRT has demonstrated efficacy in the treatment of chronic hyponatremia in patients with renal failure, and can slowly and continuously correct water-electrolyte imbalance, acid-base imbalance, and volume overload. TURP syndrome with severe hyponatremia and pulmonary edema was diagnosed; accordingly, the patient was treated with 3% hypertonic saline, furosemide, and CRRT, without the development of overt neurological sequelae.

Dexmedetomidine Resists Intestinal Ischemia-Reperfusion Injury by Inhibiting TLR4/MyD88/NF-κB Signaling.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) is a common clinical problem that occurs during various clinical pathological processes. Dexmedetomidine (DEX), a widely used anesthetic adjuvant agent, can induce protection against intestinal I/R in vivo; however, the underlying mechanism is not fully understood. In the present study, we aimed to investigate the protective effects of DEX and examine whether its mechanism was associated with the TLR4/MyD88/NF-κB signaling pathway. METHODS: Sprague-Dawley rats were pretreated with DEX and then subjected to I/R-induced intestinal injury. In vivo, intestinal histopathological examination and scoring were performed, the levels of serum intestinal fatty acid-binding protein (I-FABP), intestinal tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and expression levels of TLR4, MyD88, and NF-κB in the intestine were determined. In in vitro experiments, the human colon carcinoma cell line (Caco-2) was incubated with DEX before deprivation/reoxygenation (OGD/R) treatment. The cell viability of Caco-2 cells, the levels of lactate dehydrogenase (LDH), TNF-α, and IL-1ß in the supernatant, as well as protein expression of TLR4, MyD88, and NF-κB in Caco-2 cells, were measured. Statistical analysis was performed using SPSS version 21.0. RESULTS: DEX preconditioning significantly reduced the intestinal pathological Chiu's score, serum I-FABP, intestinal TNF-α, IL-1ß levels, and the protein expression of TLR4, MyD88, and NF-κB in the rats with intestinal I/R injury. Similarly, in vitro, DEX pretreatment protected against OGD/R-induced Caco-2 cell damage and inhibited TLR4/MyD88/NF-κB signaling, as evidenced by increased cell viability, decreased LDH activity, reduced TNF-α and IL-1ß levels, as well as downregulated TLR4, MyD88, and NF-κB protein levels. CONCLUSIONS: Our findings suggested that DEX could reduce intestinal I/R injury in rats and OGD/R damage in Caco-2 cells, and this protection might be attributed to antiinflammatory effects and inhibition of the TLR4/MyD88/NF-κB signaling pathway.

MBD1 Contributes to the Genesis of Acute Pain and Neuropathic Pain by Epigenetic Silencing of Oprm1 and Kcna2 Genes in Primary Sensory Neurons.

The transmission of normal sensory and/or acute noxious information requires intact expression of pain-associated genes within the pain pathways of nervous system. Expressional changes of these genes after peripheral nerve injury are also critical for neuropathic pain induction and maintenance. Methyl-CpG-binding domain protein 1 (MBD1), an epigenetic repressor, regulates gene transcriptional activity. We report here that MBD1 in the primary sensory neurons of DRG is critical for the genesis of acute pain and neuropathic pain as DRG MBD1-deficient mice exhibit the reduced responses to acute mechanical, heat, cold, and capsaicin stimuli and the blunted nerve injury-induced pain hypersensitivities. Furthermore, DRG overexpression of MBD1 leads to spontaneous pain and evoked pain hypersensitivities in the WT mice and restores acute pain sensitivities in the MBD1-deficient mice. Mechanistically, MDB1 represses Oprm1 and Kcna2 gene expression by recruiting DNA methyltransferase DNMT3a into these two gene promoters in the DRG neurons. DRG MBD1 is likely a key player under the conditions of acute pain and neuropathic pain.SIGNIFICANCE STATEMENT In the present study, we revealed that the mice with deficiency of methyl-CpG-binding domain protein 1 (MBD1), an epigenetic repressor, in the DRG displayed the reduced responses to acute noxious stimuli and the blunted neuropathic pain. We also showed that DRG overexpression of MBD1 produced the hypersensitivities to noxious stimuli in the WT mice and rescued acute pain sensitivities in the MBD1-deficient mice. We have also provided the evidence that MDB1 represses Oprm1 and Kcna2 gene expression by recruiting DNA methyltransferase DNMT3a into these two gene promoters in the DRG neurons. DRG MBD1 may participate in the genesis of acute pain and neuropathic pain likely through regulating DNMT3a-controlled Oprm1 and Kcna2 gene expression in the DRG neurons.

Transient Receptor Potential Ankyrin 1 and Substance P Mediate the Development of Gastric Mucosal Lesions in a Water Immersion Restraint Stress Rat Model.

BACKGROUND: Activation of substance P (SP) contributes to the development and maintenance of gastric lesions, but the mechanisms underlying the release of SP and SP-mediated damage to the gastric mucosa remain unknown. Transient receptor potential ankyrin 1 (TRPA1) is expressed in SP-positive neurons in the dorsal root ganglion (DRG) and stomach of rats. We hypothesized that water immersion restraint stress (WIRS) may activate and sensitize TRPA1 in DRG neurons, subsequently inducing the release of SP from DRG and stomach cells, causing the development of acute gastric mucosal lesions (AGML). METHODS: Changes in TRPA1 and SP expression in T8-11 DRG sensory neurons and the stomach in an AGML rat model were determined by reverse transcription polymerase chain reaction, western blotting and immunohistochemistry. The SP levels of serum and gastric mucosa were measured by using an enzyme-linked immunosorbent assay (ELISA). Gastric lesions were evaluated by histopathological changes. The TRPA1 antagonist HC-030031 and TRPA1 agonists allyl isothiocyanate were used to verify effect of TRPA1 and SP on AGML. RESULTS: SP and TRPA1 in the DRG and stomach were upregulated, and the serum and gastric mucosa levels of SP were increased after WIRS, which are closely associated with AGML. The release of SP was suppressed and AGML were alleviated following a selective TRPA1 antagonist HC-030031. TRPA1 agonists AITC increased release of SP and led to moderate gastric lesions. We confirmed that WIRS induced the release of SP in the DRG, stomach, serum and gastric mucosa, and in a TRPA1-dependent manner. CONCLUSIONS: Upregulated SP and TRPA1 in the DRG and stomach and increased serum and gastric mucosa SP levels may contribute to stress-induced AGML. TRPA1 is a potential drug target to reduce stress-induced AGML development in patients with acute critical illnesses. This study may contribute to the discovery of drugs for AGML treatment.

The effect of dexmedetomidine on haemodynamics during intracranial procedures: a meta-analysis.

OBJECTIVES: Our aim of this study is to compare the effect of Dexmedetomidine versus placebo for patients with cerebral protection during intracranial procedures. METHODS: Rev.Man 5.1 and Stata 11.0 software is used for this study to make analysis, and use a fixed-effects model (the Mantel-Haenszel method) or a random-effects model (the DerSimonian and Laird method) to merge or aggregate the weighted mean difference (WMD) or risk ratio (RR) and its 95% confidence intervals (CI) of included studies. RESULTS: Nine studies involving 404 patients with cerebral protection during intracranial procedures (experimental group: 202; control group: 202) were performed in this study. Significant differences of MAP > 100 mmHg(RR = 0.45, 95%CI = 0.29 to 0.69, P < 0.05), MAP< 60 mmHg (RR = 0.66, 95%CI = 0.43 to 1.00, P = 0.05), MAP when extubation (WMD = -12.57, 95%CI = -16.31 to -8.83, P < 0.05) and heart rate when extubation (WMD = -22.79, 95%CI = -30.57 to -15.01, P < 0.05) were observed between the two groups. There are no significant differences were found in HR > 100 bpm (RR = 0.52, 95%CI = 0.22 to 1.19, P > 0.05) and HR< 50 bpm (RR = 0.86, 95%CI = 0.31 to 2.38, P > 0.05) between the two groups. CONCLUSIONS: Our results suggested that the efficacy of Dexmedetomidine for patients with cerebral protection during intracranial procedures is better than placebo treatment.

Consequences of Surface Oxophilicity of Ni, Ni-Co, and Co Clusters on Methane Activation.

This study describes a new C-H bond activation pathway during CH4-CO2 reactions on oxophilic Ni-Co and Co clusters, unlike those established previously on Ni clusters. The initial C-H bond activation remains as the sole kinetically relevant step on Ni-Co, Ni, and Co clusters, but their specific reaction paths vary. On Ni clusters, C-H bond activation occurs via an oxidative addition step that involves a three-center (H3C···*···H)⧧ transition state, during which a Ni-atom inserts into the C-H bond and donates its electron density into the C-H bond's antibonding orbital. Ni-Co clusters are more oxophilic than Ni; thus, their surfaces are covered with oxygen adatoms. An oxygen adatom and a vicinal Co-atom form a metal-oxygen site-pair that cleaves the C-H bond via a σ bond metathesis reaction, during which the Co inserts into the C-H bond while the oxygen abstracts the leaving H-atom in a concerted, four-center (H3C···*···H···O*)⧧ transition state. Similarly, Co clusters also catalyze the σ bond metathesis step, but much less effectively because of their higher oxophilicities, much stronger binding to oxygen, and less effective hydrogen abstraction than Ni-Co clusters. On Ni-Co and Co clusters, the pseudo-first-order rate coefficients are single-valued functions of the CO2-to-CO ratio (or H2O-to-H2 ratio), because this ratio prescribes the oxygen chemical potentials and the relative abundances of metal-oxygen site-pairs through the water-gas shift equilibrium. The direct involvement of reactive oxygen in the kinetically relevant step leads to more effective CH4 turnovers and complete elimination of coke deposition on Ni-Co bimetallic clusters.

Continuous wound infusion of ropivacaine for the control of pain after thoracolumbar spinal surgery: a randomized clinical trial.

PURPOSE: A prospective randomized clinical trial was carried out to observe the analgesic efficacy of ropivacaine for postoperative pain following thoracolumbar spinal surgery. METHODS: Seventy-one patients with elective posterior thoracolumbar spinal surgery were randomly divided into two groups. Local group received 0.33 % ropivacaine by pump through the wound, and intravenous group received flurbiprofen axetil, pentazocine and palonosetron via intravenous pump. We evaluated the level of pain, the incidence of adverse reactions at 2, 4, 6, 12, 24, 36 and 48 h after operation, and the occurrence of chronic pain 3 months later. RESULTS: There were no significant differences in the pain level between the two groups. However, the incidence of nausea, vomiting and chronic pain was significantly lower in the local group. CONCLUSIONS: Our results showed that local infusion of ropivacaine achieved similar analgesic effects to intravenous delivery of analgesic drugs, but significantly reduced incidence of nausea, vomiting and chronic pain.

Cuff-leak test combined with interventional bronchoscopy benefits early extubation for patients who received tarp surgery.

PURPOSE: This study explored the performance characteristics of a cuff-leak test (CLT) combined with interventional fiberoptic bronchoscopy (FBS) for evaluating whether early nasoendotracheal extubation was possible for patients who had received transoral atlantoaxial reduction plate (TARP) internal fixation surgery. METHODS: 318 patients who underwent surgery were retrospectively analyzed (between January 2006 and December 2012). Extubation was performed by conventional approach (CA group, until December 2008) and improved approach (IA group, from January 2009) including CLT and an interventional FBS procedure. The extubation success within 1-3 days after surgery, incidence of postextubation stridor and tracheal reintubation were examined. RESULTS: More IA-treated patients experienced extubation during the first 2 days than those CA-treated, median extubation time was 3 (2, 3) days in the CA group and 2 (1, 2) days in the IA group (all P < 0.01). The incidence of stridor and reintubation was 5.69 and 0.57 % in IA and 11.98 and 4.93 % in CA, respectively (both P < 0.05). For the CLT-positive patients in the IA group that remained intubated until day 3-4, interventional FBS was applied for safe extubation and achieved 100 % success. CONCLUSION: Early extubation through IA is safe and interventional FBS assists successful extubation for CLT-positive patients who underwent TARP surgery.

Cannabinoid CB2 Receptor Mediates Nicotine-Induced Anti-Inflammation in N9 Microglial Cells Exposed to ß Amyloid via Protein Kinase C.

BACKGROUND: Reducing ß amyloid- (Aß-) induced microglial activation is considered to be effective in treating Alzheimer's disease (AD). Nicotine attenuates Aß-induced microglial activation; the mechanism, however, is still elusive. Microglia could be activated into classic activated state (M1 state) or alternative activated state (M2 state); the former is cytotoxic and the latter is neurotrophic. In this investigation, we hypothesized that nicotine attenuates Aß-induced microglial activation by shifting microglial M1 to M2 state, and cannabinoid CB2 receptor and protein kinase C mediate the process. METHODS: We used Aß1-42 to activate N9 microglial cells and observed nicotine-induced effects on microglial M1 and M2 biomarkers by using western blot, immunocytochemistry, and enzyme-linked immunosorbent assay (ELISA). RESULTS: We found that nicotine reduced the levels of M1 state markers, including inducible nitric oxide synthase (iNOS) expression and tumor necrosis factor α (TNF-α) and interleukin- (IL-) 6 releases; meanwhile, it increased the levels of M2 state markers, including arginase-1 (Arg-1) expression and brain-derived neurotrophic factor (BDNF) release, in the Aß-stimulated microglia. Coadministration of cannabinoid CB2 receptor antagonist or protein kinase C (PKC) inhibitor partially abolished the nicotine-induced effects. CONCLUSION: These findings indicated that cannabinoid CB2 receptor mediates nicotine-induced anti-inflammation in microglia exposed to Aß via PKC.

The selective ASIC3 inhibitor APETx2 alleviates gastric mucosal lesion in the rat.

This study aimed to assess the in vivo efficacy of acid sensing ion channel 3 (ASIC3) inhibitor APETx2 to alleviate acute gastric mucosal lesion (AGML) in a rat model. Thirty-six male Wistar rats were divided randomly into three groups: control group, water immersion restraint stress (WIRS) group, and APETx2 treatment group (n = 12). AGML was induced by WIRS for 6 h, and 25 microg/kg APETx2 was injected intraperitoneally before the onset of stress. Intragastric pH, ulcer index (UI) and gastric histopathological changes were measured, ASIC3 expression in thoracic dorsal root ganglia (DRG) neurons was examined by immunohistochemistry, PCR and Western blot analysis. Compared with control group, WIRS group showed obvious gastric injury with increased UI score, decreased intragastric pH and increased ASIC3 expression in DRG neurons (p < 0.05). APETx2 treatment before WIRS significantly alleviated gastric mucosal injury, decreased UI score, decreased gastric acidity and reduced ASIC3 expression in thoracic DRG neurons (p < 0.05). In conclusion, ASIC3 expression in DRG neurons projecting to the stomach is positively correlated with gastric mucosal lesion and acidosis in WIRS model. ASIC3 inhibitor APETx2 could improve gastric acidosis and alleviate AGML.

Catalytic consequences of the thermodynamic activities at metal cluster surfaces and their periodic reactivity trend for methanol oxidation.

The periodic reactivity trend and the connection of kinetics to the thermodynamic activity of oxygen are established for the oxidation of methanol on metal clusters. First-order rate coefficients are a single-valued function of the O2 -to-CH3OH ratio, because this ratio, together with the rate constants for O2 and CH3OH activation, determine the oxygen chemical potential, thus the relative abundance of active sites and bulk chemical state of the clusters. CH3OH activation rate constants on oxygen-covered Ag, Pt, and Pd and on RuO2 clusters vary with the metal-oxygen binding strength in a classical volcano-type relation, because the oxygen-binding strength directly influences the reactivities of oxygen as H abstractors during the kinetically relevant CH3OH activation step. The differences in oxygen thermodynamic activity lead to five orders of magnitude variation in rates (Pt>Pd>RuO2>Ag, 373 K), because of its strong effects on the activation enthalpy and more prominently activation entropy in CH3OH activation.

[Retracted] Intracisternal administration of an interleukin­6 receptor antagonist attenuates surgery­induced cognitive impairment by inhibition of neuroinflammatory responses in aged rats.

[This retracts the article DOI: 10.3892/etm.2014.2149.].

Effect of aquaporin-4 deficiency on intravenous anaesthetic induced hypnotic effects in mice.

The deficiency of aquaporin-4 (AQP4) has been reported to alter release of neurotransmitters in the mouse brain. However, the functional relevance of AQP4 in mediating essential components of the general anaesthetic state is unknown. The aim of the present study was to investigate the role of AQP4 in general anaesthesia in mice lacking AQP4. The hypnotic effects of propofol, ketamine, and pentobarbital in AQP4 knockout (KO) and CD1 control mice were evaluated using the behavioural endpoint of loss of righting reflex (LORR). The effects of propofol on extracellular levels of amino acids in prefrontal cortex of freely moving mice were investigated using microdialysis coupled to high performance liquid chromatography with fluorescent detection. The result showed that, after receiving ketamine or pentobarbital, LORR occurred at earlier time in KO mice than that in control animals. Intraperitoneal injection of ketamine or pentobarbital increased the duration of LORR. After the administration of propofol, the duration of LORR was significantly reduced in KO mice compared with that in controls. Propofol increased the extracellular levels of aspartate, glutamate, and GABA, but not taurine, in prefrontal cortex. There were significant differences of increase patterns of the three kinds of neurotransmitters between KO and WT mice. Notably, the duration of GABA level increase correlated with the duration of LORR in two genotypes of mice. These results provide in vivo evidence of different responses in time-dependent release of excitatory and inhibitory neurotransmitters in prefrontal cortex of the two genotypes of mice. It is suggested that changes in anaesthetic reactions in mice with AQP4 loss may be related to neurotransmitter regulation, and that normal functioning of AQP4 plays an important role in the maintenance of anaesthetic hypnosis.

Functional regulation of syntaxin-1: An underlying mechanism mediating exocytosis in neuroendocrine cells.

The fusion of the secretory vesicle with the plasma membrane requires the assembly of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein complexes formed by synaptobrevin, syntaxin-1, and SNAP-25. Within the pathway leading to exocytosis, the transitions between the "open" and "closed" conformations of syntaxin-1 function as a switch for the fusion of vesicles with the plasma membranes; rapid assembly and disassembly of syntaxin-1 clusters on the plasma membrane provide docking and fusion sites for secretory vesicles in neuroendocrine cells; and the fully zippered trans-SNARE complex, which requires the orderly, rapid and accurate binding of syntaxin-1 to other SNARE proteins, play key roles in triggering fusion. All of these reactions that affect exocytosis under physiological conditions are tightly regulated by multiple factors. Here, we review the current evidence for the involvement of syntaxin-1 in the mechanism of neuroendocrine cell exocytosis, discuss the roles of multiple factors such as proteins, lipids, protein kinases, drugs, and toxins in SNARE complex-mediated membrane fusion, and present an overview of syntaxin-1 mutation-associated diseases with a view to developing novel mechanistic therapeutic targets for the treatment of neuroendocrine disorders.

Hypercoagulable state in patients with schizophrenia: different effects of acute and chronic antipsychotic medications.

Background: Previous studies reported higher incidences of venous thromboembolism and cardiovascular disease in schizophrenia patients and higher indicators of thrombosis, thrombocyte activation, and platelet dysfunction. Objectives: To check if first-episode schizophrenia (FES) patients have a hypercoagulable state and determine whether acute and chronic antipsychotics have the same effect on blood coagulation or fibrinolysis-related biomarkers. Design: Case-control study. Methods: A total of 81 participants were grouped in FES, chronic schizophrenia (CS), and healthy controls (HCs). In addition to demographic data and clinical characteristics, immunological analyses were performed to measure plasma levels of D-dimer, plasminogen activator inhibitor-1 (PAI-1), soluble P selectin (sP-sel), tissue plasminogen activator (tPA), thrombotic precursor protein (TpP), and von Willebrand's disease factor (vWF). Results: Compared to HC group, FES patients showed higher PAI-1 (28.61 ng/ml versus 15.69 ng/ml), sP-sel (2.78 ng/ml versus 1.18 ng/ml), and TpP (15.61 µg/ml versus 5.59 µg/ml) along with a higher PAI-1/tPA (3.12 versus 2.00). Acute antipsychotic medication reduced higher PAI-1 (28.61 → 21.99), sP-sel (2.78 → 1.87), tPA (9.59 → 5.83), TpP (15.61 → 10.54), and vWF (383.18 → 291.08) in FES patients. However, plasma sP-sel and vWF in CS patients returned to the pre-treatment levels in FES patients, and PAI-1/tPA significantly decreased compared to FES patients. Conclusion: These results suggest a hypercoagulable state in FES patients and demonstrate contrast effects of acute and chronic antipsychotics on coagulation or fibrinolysis in schizophrenia patients.

Mechanism of dexmedetomidine preconditioning on spinal cord analgesia in rats with functional chronic visceral pain.

PURPOSE: To analyze the effect and mechanism of dexmedetomidine (DEX) analgesia pretreatment on functional chronic visceral pain in rats. METHODS: Rats were divided into six groups: W1, W2, W3, W4, W5, and W6. The behavioral changes and electrophysiological indexes of rats in each group before and after DEX treatment were detected. RESULTS: The levels of abdominal withdrawal reflex (AWR) in W5 and W6 groups were significantly lower than those in group W3, while the levels of thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) were significantly higher than those in group W3 (p < 0.05). The electromyographic signals of W1, W5, and W6 groups showed little fluctuation, while those of groups W2, W3, and W4 showed obvious fluctuation. TLR4 mRNA expression, IRF3, P65, and phosphorylation levels in W4, W5, and W6 groups were significantly lower than those in group W2 (p < 0.05). CONCLUSIONS: Dexmedetomidine epidural anesthesia pretreatment could significantly inhibit visceral pain response in rats with functional chronic visceral pain, and its mechanism was related to the activation of TLR4 in spinal dorsal horn tissue of rats and the activation inhibition of IRF3 and P65 in the downstream key signals.

Effect of MnO2 Polymorphs' Structure on Low-Temperature Catalytic Oxidation: Crystalline Controlled Oxygen Vacancy Formation.

MnO2 polymorphs (α-, ß-, and ε-MnO2) were synthesized, and their chemical/physical properties for CO oxidation were systematically studied using multiple techniques. Density functional theory (DFT) calculations and temperature-programmed experiments reveal that ß-MnO2 shows low energies for oxygen vacancy generation and excellent redox properties, exhibiting significant CO oxidation activity (T90 = 75 °C) and stability even under a humid atmosphere. For the first time, we report that the specific reaction rate for ß-MnO2 (0.135 moleculeCO·nm-2·s-1 at 90 °C) is roughly approximately 4 and 17 times higher than that of ε-MnO2 and α-MnO2, respectively. The specific reaction rate order (ß-MnO2 > ε-MnO2 > α-MnO2) is not only in good agreement with reduction rates (CO-TPSR measurements) but also agrees with the DFT calculation. In combination with in situ spectra and intrinsic kinetic studies, the mechanisms of CO oxidation over various crystal structures of MnO2 were proposed as well. We believe the new insights from this study will largely inspire the design of such a kind of catalyst.

Dexmedetomidine alleviates the hypoxic-ischemic brain damage via miR-20a-5p/methionine adenosyltransferase 2B axis in rat pups.

OBJECTIVE: The neuroprotective effect of dexmedetomidine (DEX) has been demonstrated in hypoxic-ischemic brain damage (HIBD) animal models, the mechanism of which will be the foothold in this work. METHODS: After establishment of HIBD rat model, the rats were treated with DEX, miR-20a-5p agomir and adenoviral methionine adenosyltransferase 2B (MAT2B) overexpression vector, and then their brain tissues were harvested. The infarction volume and pathological changes of these brain tissues were measured using the triphenyl tetrazolium chloride (TTC), Nissl and hematoxylin-eosin (HE) stainings. The levels of miR-20a-5p, Bcl-2, Bax and MAT2B in these brain tissues were detected by Real-Time PCR (RT-PCR) and western blot. The binding sites of MAT2B and miR-20a-5p were predicted using the TargetScan and verified using the dual-luciferase reporter assay. The memory deficits and spatial learning of rat pups were assessed by Morris water maze test. RESULTS: MiR-20a-5p expression was upregulated, while MAT2B expression was downregulated in rats with HIBD. MAT2B was targeted by miR-20a-5p. DEX treatment improved the neurons and hippocampal tissue damage and decreased miR-20a-5p level in brain tissues of rats with HIBD. MiR-20a-5p overexpression overturned the protective effect of DEX on brain tissues and learning and memory abilities in rats with HIBD. Moreover, DEX promoted Bcl-2 level while inhibiting Bax level in HIBD rats' brain tissues. Besides, overexpressed MAT2B reversed the effect of overexpressed miR-20a-5p on the levels of MAT2B, Bcl-2 and Bax, brain tissue damage, as well as the learning and memory abilities in rats with HIBD. CONCLUSION: DEX alleviated HIBD via the miR-20a-5p/MAT2B axis in rats.

Case report: intraoperative management of extreme hemodilution in a patient with a severed axillary artery.

We present a case of extreme hemodilution in which appropriately crossmatched blood was not available. A 53-year-old man was admitted to our hospital because of hemorrhagic shock due to multiple stab wounds. His blood type was B, Rh negative, and his intravascular fluid volume was maintained with balanced salt solution and plasma substitutes, i.e., hydroxyethyl starch. His hemoglobin reached a nadir of 0.7 g/dL and hematocrit 2.2% before being transfused. No evidence of cardiac ischemia was noted and he was discharged in good condition. Extreme hemodilution can be successfully managed by maintaining a normal blood volume, 100% oxygen, and the use of plasma substitutes.