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Herein we present the synthesis and characterization of a panel of structurally related zwitterionic piano-stool rhodium(III) and ruthenium(II) complexes. The identities of these novel complexes have been determined by NMR spectroscopy, mass spectrometry, elemental analysis and single-crystal X-ray crystallography. The stability and fluorescence property of these zwitterionic complexes were also confirmed. Zwitterionic rhodium(III) complexes Rh1-Rh4 displayed potent cytotoxic activity against A549 and HeLa human cancer cells. On the contrary, zwitterionic ruthenium(II) complexes Ru1-Ru4 presented no obvious cytotoxic activity to the test cell lines. Moreover, the trend that the introduction of fluorinated substituent and phenyl ring in the η5-CpR ring and N,N-chelating ligand, respectively, could enhance the cytotoxicity of these zwitterionic rhodium(III) complexes, were observed. The exploration of mechanism using flow cytometry displayed that the cytotoxicity of these rhodium(III) complexes was associated with the perturbation of the cell cycle and the induction of cell apoptosis. Furthermore, microscopic analysis using confocal microscopy indicated that the representative rhodium(III) complex Rh4 entered A549 cells via energy-dependent pathway and predominantly accumulated in lysosomes, thus leading to the disruption of lysosomal integrity.

The core-shell nanowires structure has increasingly attracted the attention in energetic-material applications due to the high reactive interface. However, the influences for surface density of nanowires on the exothermic capability, ignition response, even reaction process are still rarely reported, which is probability benefit to give more energy release for micron combustion. Here, CuO nanowires are prepared by electrochemical and chemical etching methods, subsequently Al is sputtered on CuO nanowires, and a series of different loading density of Al/CuO nano-thermite are prepared. As results, characterizations show that the CuO nanowires prepared by the electrochemical method has the high surface density and a homogeneous structure, which is beneficial to the contact between Al and CuO. Correspondingly, TG/DSC tests show that the heat release per unit area of nano-thermite prepared by electrochemical-sputtering is 8 times that of the product prepared by chemical-sputtering. Its obvious reduction of activation energy (181.142 kJ/mol) could be attributed to the excellence interaction of thermite components. Moreover, the high surface density structure of nano-thermite is easier to be ignited with lower ignite energy of only 10 mJ. Its significantly increase in combustion rate, flame area or intensity also demonstrated the great advantage in micron igniter or combustion devices.

A novel graphene-ferrocene nanocomposite (G-792-Fe) was designed, prepared and characterized systemically using SEM, EDS, FTIR, XPS and RAMAN methods. The as-synthesized G-792-Fe was used as a multifunctional combustion catalyst in ammonium perchlorate-hydroxyl terminated polybutadiene (AP-HTPB) propellant, and the combustion, anti-migration, safety and mechanical performances of AP-HTPB propellant were revealed. The results showed that anchoring on the surface of graphene can effectively inhibit the migration and volatilization of ferrocene compounds in AP-HTPB propellant. The excellent combustion catalytic performance of G-792-Fe on AP-HTPB propellant (burning rate of AP-HTPB propellant containing G-792-Fe increases from 13.87 mm·s−1 to 17.28 mm·s−1 at 15 MPa) is attributed to its positive effect on AP decomposition, which generates more gas-phase products beneficial to the combustion surface thermal feedback and the gaseous REDOX reaction. Additionally, the G-792-Fe presents positive effects on reducing the electrostatic sensitivity and improving the mechanical properties of AP-HTPB propellant. The ignition energy (E50) and the maximum tensile strength (σm) of AP-HTPB propellant containing G-792-Fe were increased by 24.4 mJ and 0.75 MPa respectively, compared with AP-HTPB propellant containing catocene (156.8 mJ and 1.26 MPa). The positive effects of G-792-Fe on safety and mechanical performances of AP-HTPB propellant can be due the outstanding electrical and mechanical properties of graphene-based material. Results of this study have implications concerning design and application of multifunctional combustion catalyst, which can improve the combustion performance, anti-migration performance, safety performance and mechanical properties of AP-HTPB propellant.

The seahorse is a typical suction feeder with an elongated, tubular snout and a small terminal mouth. It is important to determine the details of this unique prey-capture behavior to improve the survival rate during seahorse breeding, especially for juveniles. In this study, we described the sucking process and characterized the kinematics in juvenile lined seahorse (Hippocampus erectus) at different ages (1–30 days after parturition; DAP) using a high-speed video system, and also investigated the histological basis of the feeding-related organs, including snout, eye, and intestine. The sucking of juvenile seahorses can be divided into four steps: searching, locating, capturing, and swallowing. Seahorses capture prey mainly based on the vision system, and histological results revealed a developed visual acuity in the newborn seahorses, so that they were able to prey once after releasing from the male seahorse's brood pouch. The attack distance, maximum snout width, capture success rate, and daily food intake of juvenile seahorses increased with maturation. A remarkable inflection point, in the snout expansion rate, successful predation rate, and growth rate, occurs at about 10 DAP, when calcification of the snout bones was completed. In addition, the intestines of newborn seahorses were short and quite simple, but developed rapidly during the first 20 DAP. These findings provide a better understanding of prey capture kinematics and nutritional physiology, and will be beneficial for improving the feeding strategies for juveniles during large seahorse breeding.

rGO-Fe2O3 nanocomposites with spherical, hollow and fusiform Fe2O3 (s, h and f) microstructures have been successfully fabricated using DMF as solvent via a facile solvothermal method. The morphologies and compositions of the as-synthesized rGO-Fe2O3 (s, h and f) nanocomposites were systematically studied using SEM, TEM, XRD, FTIR, RAMAN and XPS analysis. The rGO-Fe2O3 (s, h and f) nanocomposites were used to catalyze the thermal decomposition of energetic TKX-50 and the corresponding kinetic parameters were calculated using an isoconversional model. The catalytic performance of Fe2O3 (s, h and f) during the thermal decomposition of TKX-50 was significantly improved after being anchored onto the surface of graphene oxide. The as-synthesized rGO-Fe2O3 (h) and rGO-Fe2O3 (s) nanocomposites have an excellent effect toward reducing the temperature and apparent activation energy (Ea) for TKX-50 decomposition, respectively. The excellent catalytic performance of rGO-Fe2O3 (h) nanocomposite can be attributed to its external and internal surfaces, which provide more active sites for TKX-50 decomposition. In addition, the interactions formed between rGO and Fe2O3 have a positive effect toward reducing the Ea.

Background Recent studies have implicated that matrix metalloproteinase (MMP)-9 and MMP-2 play key roles in neuropathic pain due to their facilitation of inflammatory cytokine maturation and induction of neuroinflammation. However, the role of MMP-9/2 in postoperative pain is still unclear. We previously suggested that the natural compound paeoniflorin inhibited microglia activation induced by morphine treatment. In the present study, we demonstrated that paeoniflorin could alleviate postoperative pain via specific inhibition of matrix metalloproteinases (MMPs). Methods Mice received a plantar incision surgery and their mechanical allodynia was assessed with von Frey filaments. The activity of MMP-9/2 was determined by gelatin zymography. Cell signalling was assayed by western blot and immunohistochemistry. Results The expression of MMP-9/2 was significantly increased in mice spinal cords with plantar incision surgery. Paeoniflorin remarkably suppressed the activity of MMP-9/2 and relieved plantar incision-induced mechanical allodynia. Interestingly, the administration of paeoniflorin blocked the maturation of interleukin-1β, which is a critical substrate of MMPs. Thereafter, paeoniflorin markedly suppressed microglia activation, inhibited the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and the expression of neuronal c-Fos. Conclusion These results indicated that MMP-9/2 activation in spinal microglia plays a key role in incision-induced mechanical allodynia in mice. Moreover, utilizing paeniflorin blockage of the microglia MMP-9/2 activity might represent a valuable alternative for treating postoperative pain. Significance Our results provided direct evidence for the first time that paeoniflorin can inhibit plantar incision-induced microglia TLR4/MMP-9/2/IL-1β signalling pathway and suppress postoperative pain. Thus, regulation of microglia MMP-9/2 may provide a new strategy for ameliorating postoperative pain.

The dissolution properties of 2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (Keto-RDX) in dimethyl sulfoxide (DMSO) were studied by using a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure. The heat effects, molar enthalpies (Δ diss H), and differential enthalpies (Δ dif H) of dissolution were determined. Furthermore, the corresponding kinetic equations describing the dissolution processes at the four experimental temperatures are dα/dt = 10−2.43 (1 − α)0.63 (T = 298.15 K), dα/dt = 10−2.41 (1 − α)0.67 (T = 303.15 K), dα/dt = 10−2.40 (1 − α)0.75 (T = 308.15 K), and dα/dt = 10−2.38 (1 − α)0.76 (T = 313.15 K). The determined values of the activation energy E and pre-exponential factor A for the dissolution process are 5.99 kJ mol−1 and 10−1.38 s−1, respectively.

A new class of intracellular nanoprobe, termed AuNP loaded split-DNAzyme probe, was developed to sense miRNA in living cells. Briefly, it consists of an AuNP and substrates hybridized with two half of split DNAzymes. In the absence of target miRNA, the split DNAzymes form an inactive DNAzyme motif with their substrate through partial paring at the end of each strand, and the fluorescence is quenched. Inside the cells, the target miRNA binds with both of the two half of split DNAzymes, forming the active secondary structure in the catalytic cores, which can cleave the substrates, resulting in the rupture of the substrate and recovery of the fluorescence. Meanwhile, the target is released and binds to another inactive DNAzyme motif to drive another cycle of activation. During the cyclic process, a very small number of target miRNAs can initiate the cleavage of many fluorophore-labeled substrate strands from AuNP surface, providing an amplified fluorescent signal of the target miRNA and, thus, offering high detection sensitivity.

A new class of intracellular nanoprobe, termed AuNP-based hairpin-locked-DNAzyme probe, was developed to sense miRNA in living cells. Briefly, it consists of an AuNP and hairpin-locked-DNAzyme strands. In the absence of target miRNA, the hairpin-locked-DNAzyme strand forms a hairpin structure by intramolecular hybridization, which could inhibit the catalytic activity of DNAzyme strand and the fluorescence is quenched by the AuNP. However, in the presence of target, the target-probe hybridization can open the hairpin and form the active secondary structure in the catalytic cores to yield an “active” DNAzyme, which then cleaves the self-strand with the assist of Mg2+. The cleaved two shorter DNA fragments are separated with the target. As a result, the fluorophores are released from the AuNP and the fluorescence is enhanced. Meanwhile, the target is also released and binds to another hairpin-locked-DNAzyme strand to drive another cycle of activation. In such a way, the target-recycling amplification leads t...

Metal hydrides are regarded as a series of promising hydrogen-supplying fuel for solid rocket propellants. Their effects on the energetic and combustion performances of propellants are closely related to their reaction mechanisms. Here we report a first attempt to determine the reaction mechanism of ZrH2, a high-density metal hydride, in the combustion of a double-base propellant to evaluate its potential as a fuel. ZrH2 is determined to possess good resistance to oxidation by nitrocellulose and nitroglycerine. Thus its combustion starts with dehydrogenation to generate H2 and metallic Zr. Subsequently, the newly formed Zr and H2 participate in the combustion and, especially, Zr melts and then combusts on the burning surface which favors the heat feedback to the propellant. This phenomenon is completely different from the combustion behavior of the traditional fuel Al, where the Al particles are ejected off the burning surface of the propellant to get into the luminous flame zone to burn. The findings in this work validate the potential of ZrH2 as a hydrogen-supplying fuel for double-base propellants.

The donor donor–acceptor (DD–A) FRET model has proven to have a higher FRET efficiency than donor–acceptor acceptor (D–AA), donor–acceptor (D–A), and donor donor–acceptor acceptor (DD–AA) FRET models. The in-tube and in-cell experiments clearly demonstrate that the “DD–A” FRET binary probes can indeed increase the FRET efficiency and provide higher imaging contrast, which is about one order of magnitude higher than the ordinary “D–A” model. Furthermore, MnO2 nanosheets were employed to deliver these probes into living cells for intracellular TK1 mRNA detection because they can adsorb ssDNA probes, penetrate across the cell membrane and be reduced to Mn2+ ions by intracellular GSH. The results indicated that the MnO2 nanosheet mediated “DD–A” FRET binary probes are capable of sensitive and selective sensing gene expression and chemical-stimuli changes in gene expression levels in cancer cells. We believe that the MnO2 nanosheet mediated “DD–A” FRET binary probes have the potential as a simple but powerful tool for basic research and clinical diagnosis.

A convenient route was developed to produce unsolvated KB3H8. This compound can release hydrogen and minor boranes by subsequent cleavage of its B–H and B–H–B bonds in the 150–250 °C temperature range. And pure K2B12H12 can be prepared through KB3H8 pyrolysis, which is an optional approach to produce dodecaborate compounds.

Recently, DNA tetrahedron-based sensors for intracellular detection have attracted more attention due to many interesting properties, including good structural rigidity, excellent biocompatibility, high resistance to enzymatic degradation, and the ability to enter cells without the use of transfection agents. However, the previous designs are still restricted by their lack of accuracy, reliability, and generality. Herein, to solve these limitations, we describe self-assembly of the competition-mediated FRET-switching DNA tetrahedron molecular beacon (CF-DTMB), and its applications for intracellular tumor-related mRNA detection. In brief, the recognition strand is partially complementary to its competitor, which is a hairpin stem-loop structure inserted in one edge of the DNA tetrahedron. In the absence of a target, a long domain of the recognition strand hybridizes with the competitor and makes the hairpin structure open, inducing the two labeled dyes to be spatially separated (FRET off). However, in the ...

The development of novel combustion catalysts is critical for improving combustion performance of high-energy solid propellants. In this work, a nickel-based Schiff base complex, N,N′-bis(salicylidene)ethylenediamino nickel [Ni(Salen)], as a candidate for the combustion catalyst of solid propellants, was synthesized with high purity. The effects of Ni(Salen) on the thermal decomposition reaction of FOX-7, which is closely related to its combustion properties in propellants, were systematically investigated and the corresponding mechanisms were also evaluated through comparison and analysis. Under the action of Ni(Salen), peak temperatures of the two decomposition processes of FOX-7 were reduced from 235.7 and 296.3 °C to 233.7 and 268.7 °C, respectively. The investigations into the mechanisms revealed the interactions between the Schiff base skeleton in Ni(Salen) and FOX-7, which promotes the decomposition of the remaining FOX-7. In addition, it was found that NiO, which was a decomposition product of Ni(Salen), also played an important role in promoting the thermal decomposition of FOX-7.

Ionic liquids (ILs) are acknowledged as green chemicals and favorable substitutes for volatile organic solvents, which are currently used. However, previous studies have shown that these compounds had toxicological impacts on aquatic organisms. To investigate the effects of 1-hexyl-3- methylimidazolium bromide ionic liquid ([C6mim]Br) on embryonic development and reproduction in water flea (Daphnia magna), a series of exposure experiments were conducted, including acute toxicity, maternal exposure, and chronic exposure tests. In acute toxicity experiment, D. magna neonates exhibited developmental abnormalities in the shell spine and the second antennae in a concentration-dependent manner after exposure to [C6mim]Br. The results in maternal exposure test also revealed a certain embryo-toxicity in response to [C6mim]Br in D. magna. However, the toxicity was lower than that conveyed by direct acute exposure, this indicated that the IL could act directly on organism. During the 21 days chronic exposure, the 1.6 mg/L exposure caused marked drop in the survival, molts and the number of the first brood of D. magna. Meanwhile, the total number of offspring was significantly declined in 1.6 mg/L concentration treatment groups, whereas increased in 0.2 mg/L groups. Generally, abnormalities in the offspring were significantly increased across all of the treatment groups in contrast to the control. No effect on sex differentiation was found during the experiments. These findings suggested that [C6mim]Br could affect embryonic development and reproduction in D. magna, and provided references for further study on the mechanisms underlying toxicological effects of ILs and the assessment of their potential environmental risks.

Lunar dust simulant diversification is in correspondence with the upsurge of future lunar exploration missions. It is a fast and low-cost solution to meet raw material requirements for various ground-based applications. The diversification of lunar dust simulant proposed in this paper is realized in the following five aspects: (1) basaltic pyroclast and plagioclase are confected together as feedstock; (2) partial melting technique is applied to enhance the amorphous glass in the feedstock; (3) multilevel comminution process is employed for pulverization; (4) particle dispersing technique is used to reduce the agglomeration; (5) dielectric barrier method is engaged to charge lunar dust as required. Through these procedures, prototype lunar dust simulant BHLD20 is developed; moreover, its chemistry, particle size distribution (PSD), and charging properties can be diversified and customized further. Lunar dust simulant of specified characteristics can improve the quality and reliability for various applications.

3D X-ray Microscopy (XRM) has become an established failure analysis (FA) tool for bridging fault isolation and physical failure analysis (PFA) because it enables the visualization of defects without destroying the device under test (DUT). Through workflow improvements, it offers the opportunity to improve process characterization and device qualifications. This paper describes the application of new automated scanning and image acquisition capability for repetitive XRM device inspection in defined regions of interest (ROI). Results obtained from two test matrices showed good positioning repeatability meeting accuracy requirements for both small and medium-sized test vehicles with fast acquisition times.

The precise detection of extracellular ATP, although a challenging task, is of great significance for understanding the related cell processes. Herein, we developed a ratiometric DNA nanoswitch by employing a DNA tweezer and split aptamer. The nanoswitch is composed of three specially designed ssDNA strands, namely, the central strands O1, O2, and O3. This nanoswitch can be anchored on the cell membrane by cholesterol labeled at the 3' end of O3. Initially, the DNA tweezer adopts an open state, separating the dual fluorophores and giving rise to a low FRET (fluorescence resonance energy transfer) ratio. The presence of ATP induces the binding of the two split aptamers to alter the structure of the nanoswitch from the open state to the closed state, bringing the donor and the acceptor closer together and generating high FRET efficiency. The results demonstrated that the ratiometric DNA nanoswitch can be applied for quantitative analysis and real-time monitoring of the changes in extracellular ATP. We believe that the cell surface-anchored DNA nanoswitch has promising prospects for use as a powerful tool for the understanding of different ATP-related physiological activities.

The physiological process of defecation is directly controlled by colorectal motility. The transient receptor potential ankyrin 1 (TRPA1) channel is expressed in small intestine enterochromaffin cells and is involved in gastrointestinal motility via serotonin release. In the colorectum, however, enterochromaffin cell localization is largely distinct from that in the small intestine. Here, we investigated the role of lower gastrointestinal tract TRPA1 in modulating colorectal motility. We found that in colonic tissue, TRPA1 is predominantly expressed in mesenchymal cells of the lamina propria, which are clearly distinct from those in the small intestine. These cells coexpressed COX1 and microsomal prostaglandin E synthase-1. Intracolonic administration of TRPA1 agonists induced colonic contraction, which was suppressed by a prostaglandin E2 (PGE2) receptor 1 antagonist. TRPA1 activation induced calcium influx and PGE2 release from cultured human fibroblastic cells. In dextran sulfate sodium-treated animals, both TRPA1 and its endogenous agonist were dramatically increased in the colonic lamina propria, accompanied by abnormal colorectal contractions. Abnormal colorectal contractions were significantly prevented by pharmacological and genetic inhibition of TRPA1. In conclusion, in the lower gastrointestinal tract, mesenchymal TRPA1 activation results in PGE2 release and consequently promotes colorectal contraction, representing what we believe is a novel physiological and inflammatory bowel disease-associated mechanism of gastrointestinal motility.

It is of great interest to construct DNA-functionalized gold nanoparticles (DNA-AuNPs) with a controllable number of DNA strands and relative orientations. Herein, we describe a three-dimensional (3D) molecular transfer strategy, in which a pattern of DNA strands can be transferred from a DNA icosahedron cage (I-Cage) to the wrapped AuNP surface. The results show that DNA-AuNPs produced by this method inherit DNA pattern information encoded in the transient I-Cage template with high fidelity. Controllable numbers and positions of DNA on the surface of AuNPs can be simultaneously realized by direct "printing" of a DNA pattern from the nanoshell (I-Cage) to the nanocore (AuNP), further expanding the applications of DNA nanotechnology to nanolithography. Prospectively, the customized DNA-printed nanoparticles possess great potential for constructing programmable architectures for optoelectronic devices as well as smart biosensors for biomedical applications.

A novel glutathione-responsive (GSH-responsive) star-like amphiphilic polymer (C12H25)14-β-CD-(S-S-mPEG)7 (denoted as CCSP) was designed for efficient antitumor drug delivery. The amphiphilic β-cyclodextrin (β-CD) self-polymerize in water to form a sphere with a diameter of 40–50 nm. The secondary hydroxyl groups of β-CD were modified by dodecyl to form a hydrophobic core and the primary hydroxyl groups of β-CD were decorated with PEG through disulfide bond to form a hydrophilic shell. Since the hydrophobic cavity of β-CD was maintained, the hydrophobic core formed by dodecyl as well as cavity of β-CD provided CCSP with a loading content as high as 39.6 wt%. Importantly, DOX@CCSP exhibited low drug leakage and negligible cytotoxicity in non-reductive physiological environment, while it showed rapid release and high cytotoxicity in reductive tumorous environment via the breakage of disulfide bond. In view of the above-mentioned advantages of DOX@CCSP nanocarriers such as high loading content, proper size, favorable stimulus-response release performance and low leakage, it is believed that CCSP may offer great potential to be used as an intelligent nanocarrier for anticancer drug delivery.

We report a strategy of using small cations to construct ionic liquid octahydrotriborate. The novel liquid Li(NH3)B3H8, prepared by a facile reaction of NH4B3H8 with LiH, froze below -33.4 °C and crystallized into a monoclinic unit cell with lattice parameters of a = 8.813(1) Å, b = 8.8626(1) Å, c = 8.2076(1) Å, and β = 110.1046(5)°, providing a promising functional liquid octahydrotriborate with the highest B3H8- content and lowest freezing temperature.

A series of unsaturated (16-electron) five-coordinated ruthenium (II) complexes of the type [(η6-arene)Ru(N^N)]+PF6−, where N^N is aminoimine and η6-arene is benzene (bz) (Ru1), 3-phenylpropan-1-ol (bz-PA) (Ru2), or 4-phenylbutan-1-ol (bz-BA) (Ru3), respectively, have been serendipitously synthesized via solvent (methanol)-involved rearrangement. The identity and purity of these new complexes were determined by NMR spectroscopy, elemental analysis, mass spectrometry, and X-ray crystallography techniques. Their fluorescence property and electrochemical behavior were also investigated. These complexes showed sufficient stability and exhibited higher anticancer activity toward A549 human lung cancer cells, human cervical carcinoma cells (HeLa) and hepatocellular carcinoma cell (HepG2) than cisplatin. The investigation of structure-activity relationship displayed that Ru1 with the hydrophobic groups exhibited enhanced anticancer activity in comparison to Ru2 and Ru3 containing hydroxyl groups. Notably, complex Ru1 entered A549 human lung cancer cells through a non-energy-dependent pathway and mainly accumulated in lysosomes. Moreover, Ru1 induced a dose-dependent apoptosis and sub-G1 fraction perturbation.

The Qinghai-Tibetan Plateau region has unique meteorological characteristics, with low air temperature, low air pressure, low humidity, little precipitation, and strong diurnal variation. A two-dimensional hydrodynamic CE-QUAL-W2 model was configured for the Pangduo Reservoir to better understand the thermal structure and diurnal variation inside the reservoir under the local climate and hydrological conditions on the Qinghai-Tibetan Plateau. Observation data were used to verify the model, and the results showed that the average error of the 6 profile measured monthly from August to December 2016 was 0.1°C, and the root-mean-square error (RMSE) was 0.173°C. The water temperature from August 2016 to September 2017 was simulated by inputting measured data as model inputs. The results revealed that the reservoir of the Qinghai-Tibetan Plateau was a typical dimictic reservoir and the water mixed vertically at the end of March and the end of October. During the heating period, thermal stratification occurred, with strong diurnal variation in the epilimnion. The mean variance of the diurnal water temperature was 0.10 within a 5 m water depth but 0.04 in the whole water column. The mixing mode of inflow changed from undercurrent, horizontal-invaded flow and surface layer flow in one day. In winter, the diurnal variation was weak due to the thermal protection of the ice cover, while the mean variance of diurnal water temperature was 0.00 within both 5 m and the whole water column. Compared to reservoirs in areas with low altitude but the same latitude, significant differences occurred between the temperature structure of the low-altitude reservoir and the Pangduo Reservoir (PSI value was 26.4 kg/m2, which was only 7.5% that of the low-altitude reservoir. The seasonal changes in the net heat flux received by the surface layers determined the seasonal cycle of stratification and mixing in reservoirs. This study provided a scientific understanding of the thermal changes in stratified reservoirs under the special geographical and meteorological conditions on the Qinghai-Tibetan Plateau. Moreover, this model can serve as a reference for adaptive management of similar dimictic reservoirs in cold and high-altitude areas.

Metal hydrides, which are capable of producing H2 and release much energy efficiently via combustion, are regarded as promising high-energy fuels for future advanced solid propellants. Here, we report our first attempt on the application of a high-density hydride ZrH2 in CMDB propellants containing the high-energy explosive HMX and the revelation of the combustion mechanism of ZrH2 in HMX-CMDB propellants. ZrH2 was found to be capable of enhancing the combustion of HMX-CMDB propellants effectively. Especially, hydrogen in ZrH2 was determined to play a critical role during both its intrinsic combustion and the combustion in propellants. Upon ignition, ZrH2 dehydrogenates to produce Zr and H2, followed by combustion of the decomposition products. Interestingly, H2 release results in particle fragmentation either, promoting the combustion of hydride. As for the combustion of propellant with ZrH2, in the condensed phases, the Hδ+-Hδ− interaction promotes the thermal decomposition of HMX, leading to enhanced reaction rates. The ZrH2 combustion in propellant also starts with the hydrogen-release process, followed by melting and combusting of the newly generated metallic Zr on the burning surface. Thus, the heat feedback is greatly reinforced and the reactions in the condensed phases are further speeded up. The other dehydrogenation product, H2, participates in the gaseous combustion reactions. The insights into the effects of metal hydrides on propellant combustion are believed to be of great importance for developing novel hydride fuels for solid propellants.

To date, a few of DNAzyme-based sensors have been successfully developed in living cells; however, the intracellular aptazyme sensor has remained underdeveloped. Here, the first aptazyme sensor for amplified molecular probing in living cells is developed. A gold nanoparticle (AuNP) is modified with substrate strands hybridized to aptazyme strands. Only the target molecule can activate the aptazyme and then cleave and release the fluorophore-labeled substrate strands from the AuNP, resulting in fluorescence enhancement. The process is repeated so that each copy of target can cleave multiplex fluorophore-labeled substrate strands, amplifying the fluorescence signal. Results show that the detection limit is about 200 nM, which is 2 or 3 orders of magnitude lower than that of the reported aptamer-based adenosine triphosphate (ATP) sensors used in living cells. Furthermore, it is demonstrated that the aptazyme sensor can readily enter living cells and realize intracellular target detection.

We report a supersandwich fluorescence in situ hybridization (SFISH) strategy for highly sensitive and selective in situ visualization of mRNA expression patterns at the single-cell level. This strategy uses two fluorophore-labeled signal probes to generate a supersandwich product, which in turn generates numerous signal probes located at the target mRNA position, resulting in the in situ fluorescence signal amplification.

A metal organic framework (MOF) material, Fe-benzene-1,3,5-tricarboxylate (Fe-BTC), was investigated as a candidate for the combustion catalyst of solid propellants containing ammonium perchlorate. The thermal decomposition of ammonium perchlorate (AP) was found to be evidently enhanced in the presence of Fe-BTC. Unlike the pristine AP, the thermal decomposition and phase transition of AP in the AP/Fe-BTC system occur at almost the same temperature, resulting in a reduced decomposition temperature of 243 °C, which is 36 °C lower than that of the pristine AP. Moreover, introducing 1.0 wt% of Fe-BTC to BAMO–THF propellant with AP as the oxidizer could improve its combustion performance by effectively decreasing the pressure exponents.

To improve the engine-driven performance of propellants, high-energy alloys such as Al and Mg are usually adopted as annexing agents. However, there is still room for improvement in the potential full utilization of alloy energy. In this study, we investigated how to improve combustion efficiency by decorating Al3Mg2 alloy with multilayer graphene and amorphous boron. Scanning electron microscopy and Raman tests showed that decorating with multilayer graphene and amorphous boron promoted the dispersion of Al3Mg2 alloy. The results showed that decorating with 1% boron and 2% multilayer graphene improved the combustion heat of Al3Mg2 alloy to 32.8 and 30.5 MJ/kg, respectively. The coexistence of two phases improved the combustion efficiency of the matrix Al3Mg2 alloy.

Fluorescent zwitterionic iridium complexes have been rarely reported. In this work, four fluorescent zwitterionic cyclometalated iridium complexes bearing different sulfonated iminopyridine ligands (Ir1–Ir4) were synthesized. The solid-state molecular structure of Ir1 was established by X-ray crystallography. These zwitterionic complexes are very stable in aqueous solution and have a detectable fluorescence. The structure-activity relationship toward cancer cells was observed for these complexes. Further, the fluorescence properties of these zwitterionic complexes make it possible to determine their microscopic mechanism by the cell imaging. It is noteworthy that complex Ir3 can specifically and effectively target lysosomes and induce cell death by damaging lysosomes Further, the energy-dependent pathway was involved in the uptake of Ir3 in cancer cells. In addition, the modes of cell death were also studied through flow cytometry experiments. It seems that Ir3 displayed their biological efficacy by cell-cycle arrest and the induction of cell apoptosis.

Water temperature is an important factor in aquatic environments. Dam construction, especially the construction of multiple dams in rivers, can greatly affect the downstream water temperature. Several dams, including Wudongde, Baihetan, Xiluodu, Xiangjiaba, Three Gorges, and Gezhouba, have been constructed between Panzhihua and Yichang along the Yangtze River. The aim of this paper was to quantify the impact of these dams on the water temperature downstream. One-dimensional and two-dimensional models were used to simulate the water temperatures, and the results showed that the dams had different cumulative effects on it. For example, in January, after the construction of the Xiangjiaba and Xiluodu dams, the discharge water temperature of Xiangjiaba was 3 &deg, C higher than the natural conditions, and after the construction of the Baihetan and Wudongde dams was completed, it increased by a further 2 &deg, C. The natural river ran over 416 km with no dams from the Xiangjiaba dam to the Cuntan Station. With the influence of climate and tributary inflow, the impact of upstream dams on the water temperature was mitigated by more than 48% at Cuntan Station, displaying a recovery. It seemed that the cumulative effects of dams on the discharge water temperature of the Three Gorges decreased with the increase in the upstream storage capacity from March to May, and the construction of dams even had a negative effect. From September to February of the next year, the cumulative effects increased with the increase of the upstream storage capacity, but only the total storage capacity until a certain level, where no further impact was observed.

The fiber-like bis-(dimethylglyoximato) nickel(II) complex, Ni(DMG)2 was successfully synthesized. The obtained samples were characterized by SEM-EDS, FT-IR, XRD, and XPS. The TG-DSC-FTIR-MS coupling technique was used to characterize the thermal decomposition behavior and evolved gas analysis of Ni(DMG)2. The non-isothermal decomposition reaction kinetic parameters were obtained by both combined kinetic analysis and isoconversional Vyazovkin methods. It was found that Ni(DMG)2 begins to decompose at around 280 &deg, C, and a sharp exothermic peak is observed in the DSC curve at about 308.2 &deg, C at a heating rate of 10 &deg, C&middot, min&minus, 1. The main gaseous products are H2O, NH3, N2O, CO, and HCN, and the content of H2O is significantly higher than that of the others. The activation energy obtained by the combined kinetic analysis method is 170.61 &plusmn, 0.65 kJ&middot, mol&minus, 1. The decomposition process can be described by the random nucleation and growth of the nuclei model. However, it was challenging to attempt to evaluate the reaction mechanism precisely by one ideal kinetic model.

Metal hydrides are regarded as a series of promising hydrogen-supplying fuel for solid rocket propellants. Their effects on the energetic and combustion performances of propellants are closely related to their reaction mechanisms. Here we report a first attempt to determine the reaction mechanism of ZrH

Background Activation of adenosine monophosphate–activated kinase (AMPK) has been associated with the inhibition of inflammatory nociception and the attenuation of morphine antinociceptive tolerance. In this study, the authors investigated the impact of AMPK activation through resveratrol treatment on bone cancer pain. Methods The nociception was assessed by measuring the incidence of foot withdrawal in response to mechanical indentation in rats (n = 8). Cytokine expression was measured using quantitative polymerase chain reaction (n = 8). Cell signalings were assayed by western blot (n = 4) and immunohistochemistry (n = 5). The microglial cell line BV-2, primary astrocytes, and neuron-like SH-SY5Y cells were cultured to investigate the in vitro effects. Results Resveratrol and 5-amino-1-β-d-ribofuranosyl-imidazole-4-carboxamide, the AMPK activators, significantly attenuated bone cancer pain in rats with tumor cell implantation (TCI; threshold of mechanical withdrawal, resveratrol vs. vehicle: 10.1 ± 0.56 vs. 4.1 ± 0.37; 5-amino-1-β-d-ribofuranosyl-imidazole-4-carboxamide vs. vehicle: 8.2 ± 0.17 vs. 4.1 ± 0.37, mean ± SEM); these effects were reversed by the AMPK inhibitor compound C (compound C vs. resveratrol: 6.2 ± 1.35 vs. 10.1 ± 0.56, mean ± SEM). Resveratrol has an AMPK-dependent inhibitory effect on TCI-evoked astrocyte and microglial activation. The antinociceptive effects of resveratrol were partially mediated by the reduced phosphorylation of mitogen-activated protein kinases and decreased production of proinflammatory cytokines in an AMPK-dependent manner. Furthermore, resveratrol potently inhibited inflammatory factors–mediated protein kinase B/mammalian target of rapamycin signaling in neurons. Acute pain evoked by proinflammatory cytokines in the spinal cord was significantly attenuated by resveratrol. Conclusions AMPK activation in the spinal glia by resveratrol may have utility in the treatment of TCI-induced neuroinflammation, and our results further implicate AMPK as a novel target for the attenuation of bone cancer pain.

Kansenone is a triterpene from the root of the traditional Chinese medicine, Euphorbia kansui. However, kansenone exerts serious toxicity, but the exact mechanism was not clear. In this work, the effects of kansenone on cell proliferation, cell cycle, cell damage, and cell apoptosis were investigated. The suppression of cell proliferation was assessed via the colorimetric MTT assay, and cell morphology was visualized via inverted microscopy after IEC-6 cells were incubated with different concentrations of kansenone. Reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA) content were detected for evaluating cell damage. RNase/propidium iodide (PI) labeling for evaluation of cell cycle distribution was performed by flow cytometry analysis. Annexin V-fluorescein isothiocyanate (FITC)/PI and Hoechst 33342/Annexin V-FITC/PI staining assay for cell apoptosis detection were performed using confocal laser scanning microscopy and high content screening. Moreover, apoptosis induction was further confirmed by transmission electron microscope (TEM) and JC-1 mitochondrial membrane potential, western blot and RT-PCR analysis. The results demonstrated that kansenone exerted high cytotoxicity, induced cell arrest at G0/G1 phase, and caused mitochondria damage. In addition, kansenone could up-regulate the apoptotic proteins Bax, AIF, Apaf-1, cytochrome c, caspase-3, caspase-9, caspase-8, FasR, FasL, NF-κB, and TNFR1 mRNA expression levels, and down-regulate the anti-apoptotic Bcl-2 family proteins, revealing that kansenone induces apoptosis through both the death receptor and mitochondrial pathways.

The F-substituted Mg(BH4)2·2NH3 was successfully prepared for the first time by mechanochemically reacting Mg(BH4)2·2NH3 and LiBF4 based on the structural and chemical similarity of [BH4]− and [BF4]− anions. The results indicate that the dehydrogenation properties of Mg(BH4)2·2NH3 are significantly improved by the partial substitution of fluorine for hydrogen. Hydrogen release from the F-substituted Mg(BH4)2·2NH3 is initiated at approximately 70 °C, which is an 80 °C decrease in comparison with the pristine sample. At 150 °C, the 15 mol% F-substituted sample releases ∼5.2 wt% of hydrogen within 40 min. However, only 1.2 wt% of hydrogen could be desorbed from the pristine Mg(BH4)2·2NH3 under identical conditions. Mechanistic investigations reveal that the B–H bonds in Mg(BH4)2·2NH3 are strengthened after F-substitution, which induces more ionised Hδ− in the ammoniate and consequently facilitates the local Hδ+–Hδ− combinations within the Mg(BH4)2·2NH3 molecule. In addition, the F-substitution weakens the Mg–B bonds in Mg(BH4)2·2NH3, which favours the generation of B–N bonds during dehydrogenation. These factors are the most important reasons for the improved dehydrogenation properties of F-substituted Mg(BH4)2·2NH3.

Here we introduce an enzyme-free and colorimetric detection strategy for small molecule adenosine. The approach is based on the adenosine-aptamer binding triggered liberation of an initiator strand that consecutively catalyzes DNA hairpins hybridized from singles to couples. These couples induce gold nanoparticles assembled via crosslinking, which could be visualized by a color change.

The utilization of metal borohydride ammoniates as practical hydrogen storage materials is hindered by their unfavorable exothermic dehydrogenation thermodynamics. Here, we report a first successful attempt to tailor the dehydrogenation thermodynamics of magnesium borohydride hexaammoniate (Mg(BH4)2·6NH3) through nanoconfinement into microporous activated carbon (AC). The onset temperature for hydrogen release from the nanoconfined Mg(BH4)2·6NH3 is dramatically decreased to approximately 40 °C, and more encouragingly, hydrogen desorption is endothermic in nature. The relationship between pore size and dehydrogenation behavior is established, and the critical pore size for the endothermic dehydrogenation of the nanoconfined Mg(BH4)2·6NH3 is found to be less than 4 nm. The nanoconfinement effect of carbon scaffolds is believed to be the primary reason for the change in the dehydrogenation pathway caused by incorporating Mg(BH4)2·6NH3 into microporous activated carbon. This finding opens up the possibility to achieve reversible hydrogen storage in metal borohydride ammoniates.

Innovative techniques to visualize native microRNAs (miRNAs) in live cells can dramatically impact current research on the roles of miRNA in biology and medicine. Here, we report a novel approach for live-cell miRNA imaging using a biodegradable MnO

An efficient synthesis of unsolvated KB

MicroRNAs (miRNAs) have become an ideal biomarker candidate for early diagnosis of diseases. But various diseases involve changes in the expression of different miRNAs. Therefore, multiplexed assay of miRNAs in live cells can provide critical information for our better understanding of their roles in cells and further validating of their function in clinical diagnoses. Simultaneous detection of multiple biomarkers could effectively improve the accuracy of early cancer diagnosis. Here, we develop the two-color-based nanoflares for simultaneously detecting two distinct miRNA targets inside live cells. The nanoflares consist of gold nanoparticles (AuNPs) functionalized with a dense shell of recognition sequences hybridized to two short fluorophore-labeled DNA molecules, termed "flares". In this conformation, the close proximity of the fluorophore to the AuNPs surface leads to quenching of the fluorescence. However, when target miRNAs bind to the recognition sequence, the concomitant displacement of the flare can be detected as a corresponding increase in fluorescence. The results demonstrate that the two-color-based nanoflares can simultaneously detect miR-21 and miR-141 expression levels in various live cancer cells successfully. Compared to the traditional single-color-based nanoflares, the two-color-based nanoflares could offer more reliable and practical information for cancer detection, improving the accuracy of early disease diagnosis.

Network systems, such as transportation systems and water supply systems, play important roles in our daily life and industrial production. However, a variety of disruptive events occur during their life time, causing a series of serious losses. Due to the inevitability of disruption, we should not only focus on improving the reliability or the resistance of the system, but also pay attention to the ability of the system to response timely and recover rapidly from disruptive events. That is to say we need to pay more attention to the resilience. In this paper, we describe two resilience models, quotient resilience and integral resilience, to measure the final recovered performance and the performance cumulative process during recovery respectively. Based on these two models, we implement the optimization of the system recovery strategies after disruption, focusing on the repair sequence of the damaged components and the allocation scheme of resource. The proposed research in this paper can serve as guidance to prioritize repair tasks and allocate resource reasonably.

Objectives To evaluate the wound healing process following direct pulp capping with demineralized bone matrix (DBM) and calcium hydroxide (Ca(OH)2). Methods Fifty 8-weeks-old SPF Wistar male rats were divided into two groups: one was the DBM treated group, and the other was the Ca(OH)2 treated group. Pulpotomy was performed on the maxillary first molar of one side of each rat, and the another side was left as the blank control. Rats were sacrificed after each observation period (1, 3, 7, 14 and 28 days) and specimen slices were made. Hematoxylin-Eosin (HE) staining was used for observing the changes of pulp tissue, and immunohistochemical staining was used for observing the expression of reparative dentinogenesis-related factors runt transcription factor 2 (Runx2), type I collagen (COL I), osteocalcin (OCN) and dentin sialoprotein (DSP). Results Inflammatory cell infiltration (ICI) and pulp tissue disorganization (PTD) could be observed in both the DBM and Ca(OH)2 groups at all observation periods. The DBM group showed slighter ICI on 1 and 28 days and milder PTD on 28 days, with a significant difference (P

Background The development of antinociceptive tolerance following repetitive administration of opioid analgesics significantly hinders their clinical use. Evidence has accumulated indicating that microglia within the spinal cord play a critical role in morphine tolerance. The present study investigated the effects and possible mechanisms of a natural compound, paeoniflorin, in morphine tolerance via its specific inhibition of microglial activation. Methods The microglia cell line BV-2 was used. Cytokine expression was measured using quantitative polymerase chain reaction. Cell signalling was assayed by Western blot and immunohistochemistry. Nociception was assessed in Sprague-Dawley rats and CD-1 mice using Hargreaves’ methods or the hot-plate test, respectively. Results (1) Morphine induces robust BV-2 cell activation, as evidenced by increased p38 mitogen-activated protein kinase (MAPK) phosphorylation, nuclear factor (NF)-κB translocation and proinflammatory cytokine expression. These changes are inhibited by paeoniflorin. (2) Co-administration of paeoniflorin with morphine potentiates morphine antinociception by inhibiting p38 MAPK/NF-κB signalling in the spinal cord. (3) Co-administration of paeoniflorin suppresses morphine-increased expression of toll-like receptor-4 both in BV-2 cells and within the spinal cord following chronic morphine treatment. Conclusion Paeoniflorin directly suppresses morphine-induced microglial activation and thus results in potentiation of morphine acute analgesia and attenuation of morphine chronic antinociceptive tolerance.