Propofol postconditioning ameliorates hypoxia/reoxygenation induced H9c2 cell apoptosis and autophagy via upregulating forkhead transcription factors under hyperglycemia.

BACKGROUND: Administration of propofol, an intravenous anesthetic with antioxidant property, immediately at the onset of post-ischemic reperfusion (propofol postconditioning, P-PostC) has been shown to confer cardioprotection against ischemia-reperfusion injury, while the underlying mechanism remains incompletely understood. The FoxO transcription factors are reported to play critical roles in activating cardiomyocyte survival signaling throughout the process of cellular injuries induced by oxidative stress and are also involved in hypoxic postconditioning mediated neuroprotection, however, the role of FoxO in postconditioning mediated protection in the heart and in particular in high glucose condition is unknown. METHODS: Rat heart-derived H9c2 cells were exposed to high glucose (HG) for 48 h (h), then subjected to hypoxia/reoxygenation (H/R, composed of 8 h of hypoxia followed by 12 h of reoxygenation) in the absence or presence of postconditioning with various concentrations of propofol (P-PostC) at the onset of reoxygenation. After having identified the optical concentration of propofol, H9c2 cells were subjected to H/R and P-PostC in the absence or presence of FoxO1 or FoxO3a gene silencing to explore their roles in P-PostC mediated protection against apoptotic and autophagic cell deaths under hyperglycemia. RESULTS: The results showed that HG with or without H/R decreased cell viability, increased lactate dehydrogenase (LDH) leakage and the production of reactive oxygen species (ROS) in H9c2 cells, all of which were significantly reversed by propofol (P-PostC), especially at the concentration of 25 µmol/L (P25) (all P < 0.05, NC vs. HG; HG vs. HG + HR; HG + HR + P12.5 or HG + HR + P25 or HG + HR + P50 vs. HG + HR). Moreover, we found that propofol (P25) decreased H9c2 cells apoptosis and autophagy that were concomitant with increased FoxO1 and FoxO3a expression (all P < 0.05, HG + HR + P25 vs. HG + HR). The protective effects of propofol (P25) against H/R injury were reversed by silencing FoxO1 or FoxO3a (all P < 0.05, HG + HR + P25 vs. HG + HR + P25 + siRNA-1 or HG + HR + P25 + siRNA-5). CONCLUSION: It is concluded that propofol postconditioning attenuated H9c2 cardiac cells apoptosis and autophagy induced by H/R injury through upregulating FoxO1 and FoxO3a under hyperglycemia.

Study on the Pretreatment Process and Removal Rules of Sulfur-Containing Compounds for Medium- and Low-Temperature Coal Tar.

The heteroatoms (sulfur and nitrogen) and metals (ferrum and calcium) in coal tar can easily cause the corrosion of hydrogenation equipment, catalyst poisoning, and environmental pollution. These should be removed before coal tar is hydrogenated. In this study, with the acid refining method, the effects of three polyether demulsifiers (i.e., PD1, PD2, and PD3), polyamine carboxylate demetallizers (i.e., PCD1, PCD2, and PCD3), and separation temperature on the removal of ferrum, calcium, sulfur, and nitrogen in medium- and low-temperature coal tar were determined. PD2 was selected, and the added amount was 200 µg·g-1. When the PD2 demulsifier was added alone or PD2 demulsifier with various demetallization agents was added, heteroatoms in coal tar could be effectively removed. For the experiments and analysis, the pretreatment conditions of coal tar were as follows: the addition amount of the PD2 demulsifier was 200 µg·g-1, the addition amount of the PCD3-type demetallization agent was 400 µg·g-1, and the stirring temperature was 80 °C. Before and after pretreatment, the methods of inductively coupled plasma-atomic emission spectrometer, gas chromatography-mass spectrometry (MS), and Fourier transform-ion cyclotron resonance MS were used in the present study to explore and analyze the distribution, occurrence form, and removal law of sulfur in coal tar. As revealed from the results, sulfur compounds in coal tar <360 °C fraction (light coal tar fraction, LF) before being pretreated had a lower content, which existed as benzothiophene and dibenzothiophene largely. Sulfur compounds S1 and S2 achieved the maximum relative abundance in >360 °C fraction (heavy coal tar fraction, HF). After the compounds were pretreated, the sulfur removal rate reached 40.0% in LF, and the sulfur compounds were primarily removed. For HF, the sulfur removal rate reached 20.1%. In addition, S1 compounds within the dibenzothiophene derivatives exhibiting more side chains and a larger condensation degree were basically removed. S2 compounds, mainly linked to several quinolines or more aromatic rings and thioether-aliphatic amine sulfur compounds exhibiting small molecular weight and simple structures, were relatively easy to remove. The SO class (e.g., the sulfones and thiophene-ketone group) was more difficult to remove.

Review of the risk factors for SARS-CoV-2 transmission.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, which has lasted for nearly a year, has made people deeply aware of the strong transmissibility and pathogenicity of SARS-CoV-2 since its outbreak in December 2019. By December 2020, SARS-CoV-2 had infected over 65 million people globally, resulting in more than 1 million deaths. At present, the exact animal origin of SARS-CoV-2 remains unclear and antiviral vaccines are now undergoing clinical trials. Although the social order of human life is gradually returning to normal, new confirmed cases continue to appear worldwide, and the majority of cases are sporadic due to environmental factors and lax self-protective consciousness. This article provides the latest understanding of the epidemiology and risk factors of nosocomial and community transmission of SARS-CoV-2, as well as strategies to diminish the risk of transmission. We believe that our review will help the public correctly understand and cope with SARS-CoV-2.

MnO2 Synergized with N/S Codoped Graphene as a Flexible Cathode Efficient Electrocatalyst for Advanced Honeycomb-Shaped Stretchable Aluminum-Air Batteries.

Aluminum-air batteries possess high theoretical specific capacities and energy densities. However, the desired application performance in the field of flexible electronics is limited by the rigid battery structure and slow kinetics of the oxygen reduction reaction (ORR). To address these issues, flexible, stretchable, and customizable aluminum-air batteries with a reference to honeycomb shape are composed of multilayer single battery units to achieve large scalability and start-stop control. The single aluminum-air battery combines MnO2 with N/S codoped graphene to improve the electrocatalytic activity. Benefiting from an efficient electrocatalyst and reasonable structural design, the single aluminum-air battery exhibits excellent electrochemical characteristics under deformation conditions with a high specific capacity and energy density (1203.2 mAh g-1 Al and 1630.1 mWh g-1 Al). Furthermore, the obtained honeycomb-shaped stretchable aluminum-air batteries maintain a stable output voltage over the 2500% stretching. More interestingly, the stretchable honeycomb structure not only can solve the start-stop control problem but also has the potential to reduce the self-corrosion in disposable metal-air batteries. In addition, owing to the customizable shapes and sizes, the honeycomb-shaped stretchable aluminum-air batteries facilitate the integrated application of flexible batteries in wearables.

Structure Characterization and Solubility Analysis of the Existent Gum of the Fischer-Tropsch Synthetic Crude.

The existent gum content of the Fisher-Tropsch synthetic crude exceeded the standard seriously, affecting its transportation and use. To determine the structure of the existent gum extracted from the Fisher-Tropsch synthetic crude, elemental analysis, Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS) were employed to determine the chemical structure of the gum. The Brown-Ladner method is used to calculate the average structural parameters and the average molecular formula of the existent gum. The results show that the existent gum of the Fisher-Tropsch synthetic crude is composed of heterocyclic aromatic hydrocarbons and short-carbon paraffins. Compared with petroleum gums and coal tar gums, the existent gum content of the Fisher-Tropsch synthetic crude has the characteristics of high aromaticity, short side chains, and nitrogen-containing heterocycles. After being oxidized, its aromaticity further increases, more closed loops are formed, and the side chain is further shortened. This is caused by a complex oxidation reaction during the oxidation process. Molecular dynamics simulation calculations were performed to reveal the T-stacked morphology of the existent gum of the Fisher-Tropsch synthetic crude in a mixed solvent of acetone and toluene.

Controlled preparation of interconnected 3D hierarchical porous carbons from bacterial cellulose-based composite monoliths for supercapacitors.

The controlled design and synthesis of porous carbons with anticipated microstructures and morphologies, and a high specific surface area (SSA) have been focused on for supercapacitor development. Here, hierarchical porous carbons (HPCs) with an interconnected three-dimensional morphology derived from a natural-based bacterial cellulose (BC) composite have been successfully prepared by thermally induced phase separation of poly(ethylene-co-vinyl alcohol) (EVOH) and subsequent carbonization/activation. The SSA and porous architectures can be controlled by fine-tuning the preparation conditions such as the precursor morphology and structure, activator dosage and activation temperature, and the relationships between the super-capacitive properties and the SSA and pore size distribution have been further investigated. The obtained porous carbon material possesses a hierarchical porous structure with moderate micropores, favorable mesopores, interconnected macropores, a high SSA of 2161 m2 g-1 and a maximum oxygen-dopant content of 9.99%, enabling an increase in the active materials utilization efficiency and wettability. Due to the synergistic effects of these features, the obtained porous carbon electrode used in a supercapacitor shows a high specific capacitance of 420 F g-1 at 0.5 A g-1, excellent rate performance with 75% capacitance retention at 20 A g-1, and good cycling stability with ∼96.1% retention even after 10 000 continuous charge-discharge cycles at 5 A g-1. Additionally, the assembled supercapacitor based on porous carbon displays a moderate energy density of 20 W h kg-1. The good electrochemical performance and facile effective synthesis of bio-derived carbon materials with tunable porous structures indicate promising applications in supercapacitors.

Kinetic Parameter Calculation and Trickle Bed Reactor Simulation Based on Pilot-Scale Hydrodesulfurization Test of High-Temperature Coal Tar.

At present, a few chemicals can be separated after further processing of high-temperature coal tar (HTCT) distillates, which have a lower utilization. However, hydrogenation to produce clean fuel oil has not been widely reported in literature. Thus, due to the use of new feedstocks and the implementation of more severe environmental legislations, deep hydrodesulfurization (HDS) of HTCT will face formidable challenges. A series of HDS experiments were performed in a continuous isothermal trickle bed reactor in which the reactor temperature was varied from 648 to 678 K, the pressure from 12 to 16 MPa, and the liquid hourly space velocity (LHSV) from 0.25 to 0.35 h-1, and hydrogen-to-oil ratio kept constant at 2000 L/L. Based on the experimental data, possible reaction pathways of HDS reaction were investigated, and a modified Langmuir-Hinshelwood (LH) HTCT desulfurization kinetic model was established. gPROMS software was used to obtain optimal kinetic parameters that are as follows: EA = 26,842, K 0 = 93,958, α = -1.14, n = 1.65, and m = 0.86. The model can well reproduce various working conditions and has better prediction accuracy. Some characteristics of HTCT HDS reactions were discovered; the reaction order (n) of HTCT HDS is slightly higher than that of crude oil and medium/low-temperature coal tar (M/LTCT), but the activation energy (EA) is relatively smaller. The established reactor model was used to predict the changes of the concentration of hydrogen, hydrogen sulfide, and sulfur compounds in the gas, liquid, and solid phases along the length of the reactor, respectively. The model was also used to predict the effects of pressure, temperature, and LHSV on the conversion rate of sulfur and catalyst effectiveness factors. The results showed that the LHSV has a greater impact on the conversion rate, and the pressure and temperature are less pronounced at high-severity operating conditions; the effectiveness factor is significantly smaller than that of other HDS processes, temperature has a greater effect on the effectiveness factor, followed by pressure and LHSV. The conclusion can provide a basis for further understanding the HTCT hydrotreating process.

Interaction between mechanosensitive channels embedded in lipid membrane.

The study of the gating mechanism of mechanosensitive channels opens a window to the exploration of how different mechanical stimuli induce adaptive cellular behaviors of both the protein and the lipid, across different time and length scales. In this work, through a molecular dynamics-decorated finite element method (MDeFEM), the gating behavior of mechanosensitive channels of small conductance (MscS) in Escherichia coli (E. coli) is studied upon membrane stretch or global bending. The local membrane curvature around MscS is incorporated, as well as multiple MscL (mechanosensitive channels of large conductance) molecules in proximity to MscS. The local membrane curvature is found to delay MscS opening and diminishes moderately upon membrane stretching. Mimicking the insertion of lysophosphatidylcholine (LPC) molecules into the lipid, both downward and upward bending can active MscS, as long as the global membrane curvature radius reaches 34 nm. Based on the different MscS pore evolutions observed with the presence of one or more MscLs nearby, we propose that when coreconstituted, multiple MscL molecules tend to be located at the local membrane curvature zone around MscS. In another word, as MscL "swims around" in the lipid bilayer, it can be trapped by the membrane's local curvature. Collectively, the current study provides valuable insights into the interplay between mechanosensitive channels and lipid membrane at structural and physical levels, and specific predictions are proposed for further experimental investigations.

[Analysis of Total Organic Carbon Source Differences Between New and Old Cascade Reservoirs using Carbon and Nitrogen Isotopes].

The ecological problems due to reservoir construction are causing unprecedented concern. To reveal the differences in organic carbon distribution characteristics and sediment sources of total organic carbon (TOC) between the old and new reservoirs, water samples, and sediment samples from reservoirs constructed in the three different periods of Miaowei, Gongguoqiao, and Dachaoshan were collected in November 2017. The temperature (T), dissolved oxygen (DO), TOC, redox potential (ORP), total nitrogen (TN), and total phosphorus (TP) of the water samples were measured. The isotopes 15N and 13C were used as indicators with IsoSource software to analyze the contributions of TOC sources and their source materials to the corresponding reservoir sediments, in order to explore the carbon cycle mechanism and evolution mode of reservoir. The results showed that the average concentrations of organic carbon in the waters of the Miaowei, Gongguoqiao, and Dachaoshan Reservoirs were 0.95 mg·L-1, 1.97 mg·L-1, and 4.64 mg·L-1, respectively. The range of organic carbon content in the corresponding sediments was 4.41-81.63 g·kg-1, 18.30-28.42 g·kg-1, and 9.16-14.46 g·kg-1, respectively. The cascade construction of the reservoirs resulted in a difference between the sediment sources of the new and old reservoirs and the surrounding recharge area, meaning that the TOC of the new and old reservoirs were significantly different. For the TOC of waterbodies, the difference between the thermodynamic state of water and dissolved oxygen indirectly affects the distribution trend of TOC. The sediments mainly reflect the influence of source elements, that is, the ability of the sedimentary environment to preserve organic matter was the main cause of the vertical distribution of DCS, MV, and GGQ sediments. In the evolution mode of cascade reservoir, the research shows that it can be preliminarily set as three stages. Firstly, due to the short age of MV, it is in the first stage and mainly accumulates the TOC from the upstream. GGQ is longer than the age of MV, and it is mainly used to decompose the upstream TOC, so it is defined as in the second stage. Finally, as an old reservoir, DCS mainly accumulates TOC sources around the reservoir, which can be regarded as the third stage.

Catalytically Active Sites on Ni5P4 for Efficient Hydrogen Evolution Reaction From Atomic Scale Calculation.

Ni5P4 has received considerable attention recently as a potentially viable substitute for Pt as the cathode material for catalytic water splitting. The current investigation focuses on theoretical understandings of the characteristics of active sites toward water splitting using first-principle calculations. The results indicate that the activity of bridge NiNi sites is highly related on the bond number with neighbors. If the total bond number of NiNi is higher than 14, the sites will exhibit excellent HER performance. For the top P sites, the activity is greatly affected by the position of coplanar atoms besides the bond number. Data of bond length with neighbors can be used to predict the activity of P sites as reviewed by machine learning. Partial density of state (PDOS) analysis of different P sites illustrates that the activity of P sites should form the appropriate bond to localize some 3p orbits of the P atoms. Bond number and position of neighbors are two key parameters for the prediction of the HER activity. Based on the current work, most of the low-energy surfaces of Ni5P4 are active, indicating a good potential of this materials for hydrogen evolution reactions.

[Speciation and Transformation of Phosphorus in Sediments During the Redox Cycle].

To study the mechanism of phosphorus cycling in sediment during the redox cycle, changes in physicochemical properties of overlying water and various forms of phosphorus in sediments were investigated as a way to quantify the redistribution of phosphorus. Additionally, the effect of the release flux of phosphate from sediments under controlled redox conditions was analyzed. The results showed that the redox potential Eh and the pH system, sulfur system, carbon system, and iron-related changes exhibited periodicity and played an important role in explaining the migration and transformation mechanism in the interface phosphorus of the sediment-water phase. During the redox cycle, the phosphorus content of each species varied with the redox conditions and time. Because of this, quantitative analysis based on changes in water-sediment phosphorus could be obtained. Reducible phosphorus (BD-P) and iron-aluminum-bound phosphorus (NaOH-rP) were reversibly redistributed into weakly adsorbed phosphorus (NH4Cl-P), polyphosphorus/organophosphorous (NaOH-nrP), residual phosphorus (Rest-P), and interstitial water-soluble active phosphorus (SRP). Additionally, 93.7% of phosphorus in the sediment was not released into the water phase during the reduction reaction. The 92% of change in the overlying water total phosphorus (TP) was the SRP of overlying water, which showed that the exchange of the sediment-water phase were mainly soluble active phosphorus in this cycle. According to Fick's First Law, the maximum phosphorus flux was 0.58 mg·(m2·d)-1 during reduction and 0.16-0.22 mg·(m2·d)-1 on day seven of the oxidation phase. In the oxidation stage, the diffusion flux decreased with time, while the opposite trend occurred in the reduction reaction. This indicated that the anaerobic state accelerated the diffusion of phosphorus in sediments, and that oxygen exposure decreased the phosphorus flux in sediments.

Selective hydrodeoxygenation of p-cresol as a model for coal tar distillate on Ni-M/SiO2 (M = Ce, Co, Sn, Fe) bimetallic catalysts.

Ni-M/SiO2 with different binary metals M (M = Ce, Co, Sn, Fe) prepared by an incipient impregnation method was used in the hydrodeoxygenation (HDO) of low-temperature coal tar distillate, which is rich in phenolic compounds. p-Cresol, as a model compound of the distillate, was used to evaluate the activity and selectivity of BTX products on the series of reduced Ni-M/SiO2 catalysts in a fixed bed reactor. The properties of the catalysts were characterized by N2 adsorption-desorption, ICP-AES, XRD, H2-TPR, and XPS. Benzene and toluene as the direct deoxygenation (DDO) products and cyclohexane and methylcyclohexane as the hydrogenolysis (HYD) products were detected to evaluate the selectivity of the path in the deoxygenation process. In this series of catalysts, the order of reactivity was Ni-Ce > Ni-Sn > Ni-Co > Ni-Fe > monometallic Ni. Meanwhile, the addition of Ce and Co loaded in the Lewis acid sites of the catalyst affected the electron distribution of nickel atom and its atomic arrangement on the surface of the carrier. Compared to monometallic Ni, the DDO path become dominant on Ni-Ce and Ni-Co and the selectivity for BTX products increased from 58.8% to 77.4% and 71.1%, respectively. The binary metal Sn, unlike the former two metals, formed a Ni3Sn crystal form with Ni, which resulted in significant enhancement of the HYD path while obviously increasing the reactivity.

Carvacrol attenuates traumatic neuronal injury through store-operated Ca(2+) entry-independent regulation of intracellular Ca(2+) homeostasis.

Searching for effective pharmacological agents for traumatic brain injury (TBI) treatment has largely been unsuccessful. The transient receptor potential melastatin 7 (TRPM7), a TRP channel that is essential for embryonic development, has been shown to mediate ischemic neuronal injury in vivo and in vitro, but global deletion of TRPM7 in mice is lethal. Here, carvacrol was used to investigate the protective effect of TRPM7 inhibition in an in vitro traumatic neuronal injury model. Carvacrol (0.5 and 1 mM) reduced lactate dehydrogenase (LDH) release, apoptosis and caspase-3 activation after traumatic injury in cortical neurons. These neuroprotective effects were accompanied by alleviated cytoplasmic calcium levels as measured by calcium imaging. In contrast, the thapsigargin (TG) induced store-operated calcium entry (SOCE) and the expression of SOCE related proteins in neurons were not altered by carvacrol treatment. The involvement of TRPM7 sensitive calcium influx in our in vitro model was confirmed by the results that bradykinin induced calcium influx was prevented by carvacrol in neurons. Furthermore, carvacrol significantly inhibited the induction of neuronal nitric oxide synthase (nNOS) after traumatic injury, and treatment with carvacrol and the nNOS inhibitor NLPA together had no extra effect on calcium concentration and neuronal injury. Thus, inhibition of TRPM7 function by carvacrol protects against traumatic neuronal injury, and might be a potential drug development strategy for the treatment of TBI.

Preliminary studies of a novel multifunctional wide-bore electrophoresis system.

This paper presents the results obtained from a novel multifunctional analysis platform established on the basis of wide-bore electrophoresis (WBE) and CE. The WBE­CE system integrated various analytical steps including separation, transfer, reaction, detection, and storage into a single system. During the WBE­CE process, a distinct three-electrode format was adopted to continuously separate and transfer samples between WBE and CE without the interruption of switching on-and-off the power suppliers. This continuous mode of operation also helped to eliminate the need for exactly timing the transfer of specific samples zone from WBE to CE and avoided the danger of missing specific samples. Samples representing mixtures of acids, bases, or proteins were analyzed on this system for evaluating its feasibility and applicability. The results indicated that the resolution achieved on this WBE­CE system was better than either the WBE or the CE alone. Further, samples transferred out of the WBE system could participate in online reaction, such as enzymatic reaction in the CE. Alternatively, samples from the WBE system could be transferred out and stored offline in a vial for post-transfer reaction. The results demonstrated that this WBE­CE system has the potential to be a multifunctional platform for a range of applications.