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Background The hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF)/VEGF receptor subtype 2 (VEGFR-2) pathway has been implicated in ischemia/reperfusion injury. The aim of this study was to clarify whether whole-body hypothermic targeted temperature management (HTTM) inhibits the HIF-1α/VEGF/VEGFR-2 pathway in a swine model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Methods Twenty-four domestic male Beijing Landrace pigs were used in this study. CA was electrically induced with ventricular fibrillation and left untreated for 8 min. Return of spontaneous circulation (ROSC) was achieved in 16 pigs, which were randomly assigned either to normothermia at 38 °C or to HTTM at 33 °C (each group: n = 8). HTTM was intravascularly induced immediately after ROSC. The core temperature was reduced to 33 °C and maintained for 12 h after ROSC. The serum levels of HIF-1α, VEGF, VEGFR-2, and neuron-specific enolase (NSE) were measured with enzyme immunoassay kits 0.5, 6, 12, and 24 h after ROSC. The expression of HIF-1α, VEGF, and VEGFR-2 in cerebral cortical tissue was measured by RT-PCR and Western blot analysis 24 h after ROSC. Neurological deficit scores and brain cortical tissue water content were evaluated 24 h after ROSC. Results The serum levels of HIF-1α, VEGF, and VEGFR-2 were significantly increased under normothermia within 24 h after ROSC. However, these increases were significantly reduced by HTTM. HTTM also decreased cerebral cortical HIF-1α, VEGF, and VEGFR-2 mRNA and protein expression 24 h after ROSC (all p

Multifunctional metal-organic framework-based composites display great potentials as electrode materials. Herein, highly dispersed Au nanorods were successfully encapsulated inside the zeolitic imidazolate framework ZIF-8 (AuNRs@ZIF-8) by epitaxial growth or nucleus coalescence. The microporous ZIF-8 shell functions as a protective coating to effectively prevent AuNRs from dissolution, aggregation, and migration during the electrochemical testing, while it provides numerous channels for the mass transfer of reactants to the AuNR surface. The as-synthesized AuNRs@ZIF-8 was then encapsulated in graphene oxide (GO) nanosheets to enhance the chemical resistance of the multicore-shell support, which possesses permanent porosity as well as high specific surface area and hydrophilicity. The excellent electrocatalytic performance of the resulting ternary AuNRs@ZIF-8@GO was demonstrated by the highly sensitive sensing of niclosamide, dichlorophen, carbendazim, and diuron, which outperformed the reported electrocatalysts for these four pesticides. This nanocomposite thus holds great promise as a catalyst for electrochemical sensor fabrication due to its abundant multiple active sites, enhanced catalytic activity, and remarkable stability.

A highly uniform and monodisperse silica-encapsulated Au@Ag multilayered core-shell nanorods (~ 80 nm in length) has been prepared with excellent electrocatalytic properties. Using the Au@Ag@SiO2 nanoassemblies to substantially enhance the sensitivity and the sol-gel molecularly imprinted polymer (MIP) with imprinted cavities to present special molecular recognition sites, a novel electrochemical sensing platform was rationally designed, fabricated, and tested for efficient theobromine (THB) quantification. The formation of final Au@Ag@SiO2@MIP was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The performance of the Au@Ag@SiO2@MIP modified electrode was evaluated by differential pulse voltammetry with the changes in peak current of hexacyanoferrate redox probe measured at a working potential of 0.2 V (vs. saturated calomel electrode) as determination signal. Under optimal conditions, the quantitation of THB was attained in a broad linear range from 10 nM to 100 μM with a detection limit of 8.0 nM. The selectivity of Au@Ag@SiO2@MIP was examined according to its recognition to THB and the interferents. Finally, the sensing platform was successfully applied to extract and determine THB from food, biological, and environmental samples with acceptable recoveries (92.20–107.1%) and relative standard deviation

Here, we report a three-dimensional (3D) network molecularly imprinted polymer (MIP) on electrode surface to achieve an efficient and specific detection of theophylline in foodstuffs, using theophylline as the template molecule, mesoporous silica nanospheres (MSNs) as the signal transducer to shuttle electrons, and both phenyltriethoxysilane and pyrrole as functional monomers. The electron microscope images reveal the presence of well-distributed hierarchically MSNs with a pomegranate-like morphology, topped with MIP uniform layer. Electrochemical characterizations were carried out to monitor the properties of the resulting sensing platform based on the MIP/gate effect employing hexacyanoferrate molecules as the electrochemical probe. The data show that due to the high conductivity and electron transfer ability of the prepared theophylline-imprinted membrane, this method exhibits excellent sensitivity and binding affinity with a linear dynamic concentration range in excess of six orders of magnitude and low detection limit (0.66 nM), meeting the requirements of theophylline trace analysis.

Objective This study aimed to identify whether esmolol attenuates cerebral cortex microcirculation blood flow due to epinephrine in prolonged ventricular fibrillation (VF) and cardiopulmonary resuscitation (CPR), and may improve neurological prognosis. Methods Male pigs were randomized into the esmolol+epinephrine group (group EE), the epinephrine group (group EP), and the normal saline group (group NS) (n = 8 each group). Untreated VF for 8 minutes was induced in pigs. After CPR for 2 minutes, group EE received esmolol (500 µg/kg)+epinephrine (20 µg/kg), group EP received epinephrine 20 µg/kg, and group NS received 5 mL normal saline. Then, a 120 J electric shock was delivered. If the return of spontaneous circulation (ROSC) failed, epinephrine (20 µg/kg) was repeated in group EP and EE, followed by another 2 minutes of CPR, a 150 J electric shock was delivered every 2 minutes until ROSC. Cerebral microcirculation images were obtained at 0.5, 6, 12, and 24 hours by cranial windows after ROSC. Cerebral performance category scores and neurological deficit scores (NDS) were calculated. The frontal cortices were harvested after the animals were euthanized. Results The NDS, the perfused vessel density, and the microcirculatory flow index of group EE were better than other two groups. The morphology of endothelial cells in the group EE remained intact; however, it was destroyed in the group EP. Conclusions Administration of esmolol with epinephrine may alleviate the impairment of cerebral microcirculation blood flow caused by the administration of epinephrine in prolonged VF and thereby improves neurological outcomes in a swine model.

Objective This study aimed to clarify whether therapeutic hypothermia protects against cerebral edema following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in a porcine model via regulating the angiopoietin-Tie-2 ligand-receptor system. Methods Male pigs were randomized into the therapeutic hypothermia group, the normothermia group or the sham control group. CA was induced in pigs by untreated ventricular fibrillation for 8 min. Brain edema was determined by measuring the cerebral cortical water content at 24 h after the return of spontaneous circulation (ROSC). The serum levels of angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), tyrosine kinase with immunoglobulin-like loop epidermal growth factor homology domain 2 (Tie-2), and S100B were measured using enzyme immunoassay kits at 0.5, 6, 12 and 24 h after ROSC. The levels of the Ang-1, Ang-2, phosphorylated Tie-2 and Tie-2 proteins in the cerebral cortex at 24 h after ROSC were determined by Western blotting. Results Therapeutic hypothermia lessened brain cortex edema, alleviated histopathology injury, and improved neurologic outcomes at 24 h after ROSC. Therapeutic hypothermia inhibited the CA- and CPR-induced increases in serum Ang-2 protein expression and the Ang-2/Ang-1 ratio and attenuated the decrease in serum Ang-1 expression. Therapeutic hypothermia also increased the protein expression of Ang-1 and the phosphorylated Tie-2/Tie-2 ratio and inhibited the expression of Ang-2 in the cerebral cortex at 24 h after ROSC. Conclusions Based on our experiment, therapeutic hypothermia decreased cerebral edema after CA, which may be, at least in part, related to its ability to modulate the expression of components of the Ang-Tie-2 system.

The effect of mild hypothermia (MH) on microcirculation after resuscitation from cardiac arrest is controversial. The aim of this study was to determine whether MH improves or aggravates the disturbance of cerebral microcirculation. Twenty domestic male pigs were randomized into the MH group (n = 8), non-hypothermia (NH) group (n = 8) or sham operation group (n = 4). In the MH group, the animals were initiated rapid intravascular cooling at 1 h after return of spontaneous circulation (ROSC) from 8 min ventricular fibrillation, and the core temperature was reduced to 33 °C for 12 h and then rewarmed to 37 °C. In the NH group, animals did not receive hypothermia treatment after ROSC. In the sham operation group, the same surgical procedure was performed, but without inducing ventricular fibrillation and hypothermia treatment. The cerebral microvascular flow index (MFI) of large microvessel (diameter > 20 μm) and small microvessel (diameter

A highly uniform and monodisperse silica-encapsulated Au@Ag multilayered core-shell nanorods (~ 80 nm in length) has been prepared with excellent electrocatalytic properties. Using the Au@Ag@SiO

Our previous study found that mild hypothermia (MH) after resuscitation reduced cerebral microcirculation, but the mechanism was not elucidated. The aim of this study was to clarify changes of endothelin-1 (ET-1) and nitric oxide (NO) systems in brain tissue during hypothermia after resuscitation. Twenty-six domestic male Beijing Landrace pigs were used in this study. MH was intravascularly induced 1 h after resuscitation from 8-min ventricular fibrillation. Core temperature was reduced to 33 °C and maintained until 8 h after resuscitation, and then animals were euthanized. ET-1 and NO levels in brain tissue and peripheral plasma were measured. Expression of endothelin-converting enzyme-1 (ECE-1), endothelin A receptor (ET-AR), endothelin-B receptor, and nitric oxide synthase (NOS) in brain tissue was determined by Western blot analysis. Compared with non-hypothermia (NH) treatment, MH after resuscitation significantly increased the level of endothelin-1 and reduced the level of NO in peripheral blood and brain tissue. Cerebral expression of ECE-1 and ET-AR was significantly increased during MH after resuscitation. Moreover, MH significantly decreased inducible NOS expression compared with the NH group. The ET-1 system is activated, while inducible NOS is inhibited in brain tissue during MH after resuscitation.

Vibration signals from On-Load Tap Changers (OLTC) contain much information about the condition of OLTC. Therefore, condition assessment based on vibration signals has attracted the attention of many scholars in recent years. Including time-domain parameters and frequency-domain parameters are extracted from vibration signals to characterize the condition of OLTC. In order to obtain these parameters, some simulated experiments on OLTC are taken. Indeed, there are some differences between vibration signals from good OLTC and faulty OLTC. However, almost all the simulated experiments are carried out without load current. And OLTC is operated with load current which reaches to hundreds of amperes in practical. In this paper, in order to analyze the influence of load current on vibration signals, the signals are measured from the same OLTC under different load currents. The experiment results show that there is no significant influence of load current on time-domain waveform of vibration signal. However, as the amplitude of the current increases, the frequency domain characteristics of the signals show regular changes.

Antibiotic pollution as a hot issue of global concern is extraordinarily sought after due to the deleterious consequences on ecosystems and human health from the excessive utilization and deficient management. Achieving determination of antibiotics residues in food is greatly crucial but remains challenging. In this work, a rational strategy was employed to fabricate chromium (III) terephthalate MOF (MIL-101) hierarchical hollow cages through crystal growth and subsequent acid etching processes. The material has been characterized using several characterizations such as scanning electron microscopy, transmission electron microscopy, and X-ray powder diffraction, showing the porous MIL-101 microspheres were made of large inner cavity and single-crystalline shell. An electrochemical sensor based on the hollow MIL-101 was then developed for the determination of nitrofurazone (NFZ). Electrochemical measurements indicate that the hollow MIL-101 has highly electrocatalytic activity and excellent voltammetric response towards the NFZ oxidation, exhibiting as a wide linear range of 0.030–55 μM and a low detection limit of 10 nM (S/N = 3). Moreover, detection of NFZ in food samples was carried out by standard addition method. Acceptable result with recovery of 93.2–103% was obtained for six parallel measurements. Our work provides a promising strategy to construct electrochemical sensors with extended applicability for analysis in complex food matrices.

Purpose: To investigate the effect of intravascular cooling on renal function after resuscitation. Methods: Twenty four pigs were randomized into three groups (n=8 in each group): therapeutic hypothermia group (TH group), normothermia group (NH group) and sham operation group (SHAM group). After 6 minutes of untreated VF, CPR was performed. Upon ROSC, the TH group received the intravascular cooling. The NH and SHAM group did not undergo therapeutic hypothermia. Haemodynamic parameters were recorded. The bloods were analyzed for serum creatinine (sCr), CysC and NGAL. The kidney was surgically removed observe pathologic changes under a light microscope. Results: The sCr increased in both TH and NH groups after ROSC, compared to baseline. Between two groups, the sCr and creatinine clearance (Cc) showed lower level in the TH group. The urine volume per hour in the TH group were higher during cooling. After resuscitation, NGAL and CysC in the NH group were higher than in the TH group. Under the light microscope, compared with the TH group, the renal injury was prominent in the NH group. Conclusion: Mild hypothermia had a protection to renal ischemia reperfusion injury after resuscitation.

Background We utilized a porcine cardiac arrest model to compare early sequential hypothermia (ESH) with delayed hypothermia (DH) and no hypothermia (NH) to investigate the different effects on cerebral function after resuscitation. Methods After return of spontaneous circulation (ROSC), resuscitated 24 pigs divided into three groups. The ESH group implemented early sequential hypothermia immediately, and the DH group implemented delayed hypothermia at 1 h after ROSC. The core temperature, hemodynamic parameters and oxygen metabolism were recorded. Cerebral metabolism variables and neurotransmitter in the extracellular fluid were collected through the microdialysis tubes. The bloods were analyzed for venous jugular bulb oxygen saturation, lactate and neuron specific nolase. The cerebral function was evaluated using the cerebral performance category and neurologic deficit score at 72 h after ROSC and cerebral histology in the right posterior frontal lobe were collected. Results ESH reached the target temperature earlier and showed more favorable outcomes of neurological function than DH. Specifically, early sequential hypothermia reduced cerebral oxygen and energy consumption and decreased extracellular accumulation of neurotransmitters after resuscitation and protected the integrity of the BBB during reperfusion. Conclusions Early sequential hypothermia could increase the protection of neurological function after resuscitation and produce better neurological outcomes. The institutional protocol number: 2010-D-013.

Mild hypothermia improves survival and neurological recovery after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). However, the mechanism underlying this phenomenon is not fully elucidated. The aim of this study was to determine whether mild hypothermia alleviates early blood-brain barrier (BBB) disruption. We investigated the effects of mild hypothermia on neurologic outcome, survival rate, brain water content, BBB permeability and changes in tight junctions (TJs) and adherens junctions (AJs) after CA and CPR. Pigs were subjected to 8 min of untreated ventricular fibrillation followed by CPR. Mild hypothermia (33°C) was intravascularly induced and maintained at this temperature for 12 h, followed by active rewarming. Mild hypothermia significantly reduced cortical water content, decreased BBB permeability and attenuated TJ ultrastructural and basement membrane breakdown in brain cortical microvessels. Mild hypothermia also attenuated the CPR-induced decreases in TJ (occludin, claudin-5, ZO-1) and AJ (VE-cadherin) protein and mRNA expression. Furthermore, mild hypothermia decreased the CA- and CPR-induced increases in matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) expression and increased angiogenin-1 (Ang-1) expression. Our findings suggest that mild hypothermia attenuates the CA- and resuscitation-induced early brain oedema and BBB disruption, and this improvement might be at least partially associated with attenuation of the breakdown of TJ and AJ, suppression of MMP-9 and VEGF expression, and upregulation of Ang-1 expression.

The homogenous precursor has been prepared using a mixed aqueous solution of Ni(NO3)2•6H2O, Co(NO3)2•6H2O, Mn(NO3)2 and LiNO3 as metal sources and citric acid as chelating agent and fuel. The nanocrystalline LiNi1/3Co1/3Mn1/3O2 powder was rapidly synthesized by deflagrating the dried precursor in oxygen. The as-synthesized LiNi1/3Co1/3Mn1/3O2 powder has a rhombohedral crystal system with an impurity phase of Li2MnO3. The mean crystallite size of as-synthesized powder was 40.89 nm. The annealed LiNi1/3Co1/3Mn1/3O2 powder was mainly consisted of particle agglomerates with the primary particles size of 100-300 nm. The high initial capacities of 208.0 mAh•g-1 (2.8-4.6 V) and 173.6 mAh•g-1 (2.8-4.3 V) were discharged at the rate of 0.05 C, respectively. Its capacity retentions were 89.3% and 93.4% within the voltage range of 2.8-4.6 V and 2.8-4.3 V at 0.1 C after 20 cycles, respectively. The results suggest that the deflagration synthesis holds potential to rapidly prepare nanocrystalline LiNi1/3Co1/3Mn1/3O2 cathode material.

Ti-doped spinel LiMn2O4 is synthesized by solid-state reaction. The X-ray photoelectron spectroscopy and X-ray diffraction analysis indicate that the structure of the doped sample is $$ {\hbox{Li}}\left( {{\hbox{M}}{{\hbox{n}}^{3 + }}{\hbox{Mn}}_{1 - x\,}^{4 + }{\hbox{Ti}}_x^{4 + }} \right){\hbox{O}}{}_4 $$ . The first principle-based calculation shows that the lattice energy increases as Ti doping content increases, which indicates that Ti doping reinforces the stability of the spinel structure. The galvanostatic charge–discharge results show that the doped sample LiMn1.97Ti0.03O4 exhibits maximum discharge capacity of 135.7 mAh g−1 (C/2 rate). Moreover, after 70 cycles, the capacity retention of LiMn1.97Ti0.03O4 is 95.0% while the undoped sample LiMn2O4 shows only 84.6% retention under the same condition. Additionally, as charge–discharge rate increases to 12C, the doped sample delivers the capacity of 107 mAh g−1, which is much higher than that of the undoped sample of only 82 mAh g−1. The significantly enhanced capacity retention and rate capability are attributed to the more stable spinel structure, higher ion diffusion coefficient, and lower charge transfer resistance of the Ti-doped spinel.

Polypyrrole (PPy) films doped by p-toluenesulfonic (PTS) ion were prepared by pulse current polymerization (PCP PPy) and direct current polymerization (DCP PPy) in aqueous solution. During polymerization of DCP PPy films, the sustained high anodic potentials can result in overoxidation and –CH2– formation at pyrrole rings, which was confirmed by the FTIR spectroscopy. PCP PPy films exhibited more homogeneous and smoother appearance than DCP PPy films. The apparent diffusion coefficient of PCP PPy films was one order of magnitude bigger than that of DCP PPy films, which was closely correlated with the more ordered structure of PCP PPy films confirmed by XRD. When the scanning rate reached up to 500 mV s−1, the CV curves of PCP PPy films showed rectangular shape within voltage range of −0.8 V to +0.8 V. High charge/discharge rate of PCP PPy films can be attributed to well wettability, very small charge transfer resistance, high electronic conductivity and ions apparent diffusion coefficient. After 50,000 charge/discharge cycles, the specific capacitance of PCP PPy films only decreased by 14% at a charge/discharge current of 20 A g−1 within voltage range of 0–0.4 V.

Spinel LiMn2O4 is one of the cathode active materials for the rechargeable lithium-ion batteries with the most potential, but suffers from a fast capacity fade when cycling at elevated temperatures (55 °C). Spinel LiMn1.97Ti0.03O4 coated with aluminum nitrate is heat-treated at various temperatures. The sample treated at low temperature (500 °C) exhibits porous Al2O3 layer coated on the surface, and little Al ion diffusing into the spinel structure. As for the sample treated at mid-temperature (700 °C), it exhibits double layers coated on the surface: the inner layer is LiAlxMn1.97−xTi0.03O4 solid solution and the outer layer is compact Al2O3 metal oxides. When the heat-treatment temperature increases to a high level (850 °C), nearly all the Al ion diffusing into the structure to form Al doped solid solution layer coated on the spinel. The relationship between the structure of the modified samples and their electrochemical properties is investigated. The galvanostatic charge–discharge results show that those surface-modified samples exhibit improved cycling performance compared to LiMn1.97Ti0.03O4; and the sample treated at mid-temperature delivers the best capacity retention, especially at 55 °C. The improved cycling performance is ascribed to the coated layers of Al2O3 and LiAlxMn1.97−xTi0.03O4 on the spinel particles. The Al2O3 layer could reduce the HF damage by scavenging of HF. While the LiAlxMn1.97−xTi0.03O4 layer could enhance the stability of the spinel structure due to the stronger Al–O bond; moreover, this coating layer having the same spinel structure with the LiMn1.97Ti0.03O4 core material would not hinder the lithium ion diffusion. The sample treated at mid-temperature has the double layers coated on the surface, and its Al2O3 coating becomes compact and thin which could effectively block the direct contact between the electrolyte and spinel particles as well as reduce the lithium ion diffusion distance in the inactive layer, leading to greatly improved capacity retention.

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Li 2 MnO 3 stabilized LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode materials are discussed by x Li 2 MnO 3 ·(1 − x )LiNi 1/3 Co 1/3 Mn 1/3 O 2 ( x = 0.3 and 0.7) solid solutions. The solid solutions were synthesized by annealing the mixing LiNO 3 , Mn(NO 3 ) 2 and LiNi 1/3 Co 1/3 Mn 1/3 O 2 powder at 900 °C for 12 h, and it was found that the cathode particle size increased from 200–300 to 300–500 nm. The pristine LiNi 1/3 Co 1/3 Mn 1/3 O 2 showed the 30th discharge capacity of 174.5 mAh g −1 . Our results indicated that the introduction of Li 2 MnO 3 in the cathode could increase performance. 0.3Li 2 MnO 3 ·0.7LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode shows higher discharge of 182.0 mAh g −1 in the 30th cycle. And the discharge capacity of 214.1 mAh g −1 was obtained when the Li 2 MnO 3 content increased to 0.7. Moreover, the cyclic performance at 55 °C was also increased by Li 2 MnO 3 . For instance, the discharge capacities were 191.2 mAh g −1 ( x = 0.3) and 229.3 mAh g −1 ( x = 0.7) and the capacity retentions are 94.9% and 91.4% after 40 cycles, respectively. The DFT calculations show that stable Li 2 MnO 3 -enriched layer is as a result of enhanced performance.