Search

Enzyme immobilization provides ideal operating conditions for enzymes stabilization and sustainable recycling. In this work, as a kind of clay material, montmorillonite (MTL) was chosen for immobilizing the β-glucosidase extracted from Agrocybe aegirit. The immobilized β-glucosidase via partly cross-linking enzyme aggregates (pCLEAs) formed by self-catalysis provided biocatalysts with satisfactory thermal and pH stability. Compared to the glutaraldehyde cross-linked, the immobilized β-glucosidase (β-G-pCLEAs@MTL) exhibited significantly higher immobilization efficiency (IE) and immobilization yield (IY), which were 80.6% and 76.9%, respectively. The β-G-pCLEAs@MTL also showed better stability and preferable reusability. And the activity of the β-G-pCLEAs@MTL remained 85.0% after 5 cycles and 74.7% after 10 cycles. Therefore, the method based on the pre- crosslinking to form pCLEAs and after-immobilization can effectively improve IY and IE. In addition, MTL seems to be a good alternative carrier to immobilize other enzymes for industrial application.

As a new environmentally friendly and sustainable green solvent, deep eutectic solvent (DES) was considered to be the most suitable alternative solvent for ionic liquids, with wide application. In ...

Background Environmental noise exposure is linked to neuroinflammation and imbalance of the gut microbiota. Promoting gut microbiota homeostasis may be a key factor in relieving the deleterious non-auditory effects of noise. This study aimed to investigate the effect of Lactobacillus rhamnosus GG (LGG) intervention on noise-induced cognitive deficits and systemic inflammation in rats. Methods Learning and memory were measured using the Morris water maze, while 16S rRNA sequencing and gas chromatography-mass spectrometry were used to analyze the gut microbiota and short-chain fatty acid (SCFA) content. Endothelial tight junction proteins and serum inflammatory mediators were assessed to explore the underlying pathological mechanisms. Results The results indicated that LGG intervention ameliorated noise-induced memory deterioration, promoted the proliferation of beneficial bacteria, inhibited harmful bacteria, improved dysregulation of SCFA-producing bacteria, and regulated SCFAs levels. Mechanistically, noise exposure led to a decrease in tight junction proteins in the gut and hippocampus and an increase in serum inflammatory mediators, which were significantly alleviated by LGG intervention. Conclusions Taken together, LGG intervention reduced gut bacterial translocation, restored gut and blood-brain barrier functions, and improved gut bacterial balance in rats exposed to chronic noise, thereby protecting against cognitive deficits and systemic inflammation by modulating the gut-brain axis.

In this paper, sheet-like porous CuO (p-CuO), which was prepared using a hydrothermal-annealing method, has been first selected as an oxidizer to prepare n-Al/p-CuO/GO nanoenergetic composites. The...

A porous CuN3 film has been facilely synthesized by a sustainable electroassisted azidation methodology using the template of porous Cu as a precursor. Such porous CuN3 films show excellent perform...

Chloramphenicol(CAP) is an antifungal agent approved for use in aquarium. However, CAP residue imparts serious adverse effect on human health as well as the ecology. Thus, keeping track of CAP in aquatic products and its environmental metabolites are of great importance. Herein, we developed a novel and neat electrochemical aptasensor for the detection of simulated CAP residual in a sandwich fashion. The screen-printed carbon electrode was employed as the sensing platform and electrodeposited with peculiar nanogolds to enhance the electrochemical performance. For the specific recognition of such small target, a pair of chloramphenicol-binding aptamers, the primary Apt1 and the secondary Apt2, were tailored as an artificial single-chained antibody couple, of which the thiolated Apt1 stood on the coated working substrate to capture the analyte, while the biotinylated Apt2 rallied the signal output. In the presence of CAP, Apt1 at the lower place cooperated with the upper Apt2 pinched CAP together. After that, the reporter avidin-conjugated horseradish peroxidase associated atop the mounted biotin labels, resulting in an electrocatalytic amplification. In whole, this modular biosensing construction would set a paradigm not just for practicable checkpoint quarantine or point-of-care testing, but potentially adaptable for technological fusion with “Internet Plus” and “Internet of Things”.

It is highly desired but still remains challenging to design a primary explosive-based nanoparticle-encapsulated conductive skeleton for the development of powerful yet safe energetic films employed in miniaturized explosive systems. Herein, a proof-of-concept electrochemical preparation of metal-organic frameworks (MOFs) derived porous carbon embedding copper-based azide (Cu(N

The CuO micro/nanowires film has been prepared successfully on a Cu substrate using a combination of an electrochemical anodization and an annealing treatment. Its morphology and phase composition ...

Water splitting has been considered as one of the most promising strategies for renewable energy production. The process of water electrolysis is greatly influenced by the sluggish kinetics of the oxygen evolution reaction (OER). Therefore, it is necessary to develop a very effective catalyst for improving OER performances. The electronic properties and morphological structure of electrocatalysts can significantly affect their OER performance. Electrocatalysts with the morphology of dendrite can expose more active sites which would enhance the OER activity. Here, the 3D dendritic Ni@Ni(Fe)OOH core-shell material has been developed on nickel foam (NF) with a controllable morphology and composition using an extremely simple and fast method. The doping of Fe can effectively modulate the morphology and the electronic structure of Ni@NiO to improve the intrinsic activity of active sites. The porous dendritic core-shell structure could allow more active sites to grow and transport electrolyte faster. At the same time, the internal Ni core can work as fast electronic transfer networks. As a result, the optimized Ni@Ni(Fe)OOH/NF shows a great catalytic performance for OER with an overpotential of 226 mV cm−2 at 10 mA cm−2 and an excellent stability in alkaline solution. The results given in paper may bring important implications for the development of a series of hydrogen and oxygen catalysts.

The design and synthesis of highly efficient electrocatalysts for OER are important for energy storing applications. In this communication, Cu(TCNQ)2 nanorod arrays have been designed and synthesized successfully with a Cu(Fe)OOH nanosheet shell by using a short oxidation process of Cu(TCNQ)2 and subsequently an ultrafast ion exchange reaction. They are expected to combine a variety of desired merits including a simple and rapid preparation process, a large specific surface area, high conductivity and multiple electrocatalytic active sites. All the worthy characteristics which make Cu(TCNQ)2@Cu(Fe)OOH are endowed with an excellent OER catalytic performances with the required overpotential of 261 mV at 25 mA cm−2 only. The present work not only produces a good OER catalyst but also provides us a new idea to design efficient OER electrocatalysts.

The compatible catalytic structure of NiCo2O4 was modified into multi-shelled hollow spheres by one-pot synthesis, followed by heat treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer–Emmet–Teller (BET) and N2 adsorption–desorption approaches were used for the characterizations of nanoparticles and multi-shelled hollow porous structures and the morphologies and crystal structures of these hollow spheres, respectively. Differential scanning calorimetry (DSC) was adopted for comparing the thermal decomposition performances of ammonium perchlorate (AP) catalyzed by adding different contents of multi-shelled NiCo2O4 hollow spheres. Impressively, the experimental results showed that the NiCo2O4 hollow spheres exhibited more excellent catalytic activity than NiCo2O4 nanoparticles as a result of their large specific surface areas, good adsorption capacity and many active reduction sites. The decomposition temperature of AP with multi-shelled NiCo2O4 hollow spheres could be reduced up to 322.3 °C from 416.3 °C. Furthermore, a catalytic mechanism was proposed for the thermal decomposition of AP over multi-shelled NiCo2O4 hollow spheres based on electron transfer processes.

Direct ink writing promotes ink formulation design gradually become a hotspot in the application research of nanothermite. In order to obtain an energetic ink with a certain mechanical strength and formability, it is necessary to compound the energetic material with an inert binder. The inert component will not only reduce the sensitivity and energy release efficiency of energetic systems, but also affect its application in micro ignition devices. Based on the thermal gelation behavior of hydroxypropyl methylcellulose (HPMC), the nAl/pCuO/HPMC ink was prepared by HPMC, nano aluminum powder (nAl), and sheet-like porous CuO (pCuO). It has found out that the energetic ink has a favorable printing accuracy when the HPMC content is 7 wt%. To compare the influence from the size and morphology of copper oxide and aluminum on ink printing and reaction performances, the mAl/pCuO/HPMC, nAl/nCuO/HPMC and nAl/mCuO/HPMC inks have been prepared using the same way. Due to the large particle size of the components, nAl/mCuO/HPMC cannot be printed continuously during the printing process. For the mAl/pCuO/HPMC, it cannot form self-sustaining combustion on the glass substrate when the ink is a single layer. The activation energy results show that nAl/pCuO/HPMC has the smallest value (68.39 kJ/mol). The calculated burning rate of nAl/pCuO/HPMC (32.56 cm/s) is about 6 times than that of nAl/nCuO/HPMC system (5.28 cm/s). The ignition performance test shows that only the nAl/pCuO/HPMC system can be successfully ignited by a SCB micro igniter when the HPMC content is 7 wt%. Meanwhile, the pressure test indicates that the nAl/pCuO/HPMC system (7 wt% HPMC, Ф=1.4) has the shortest pressure rising time (46.7 μs), but the largest pressurization rate (1661.7 GPa/s).

Pluripotency of a DNA tetrahedron (DNATT) has made the iconic framework a compelling keystone in biosensors and biodevices. Herein, distinct from the well-tapped applications in substrate fabrication, we focus on exploring their tracing and signaling potentials. A homologous family of four isostructural DNATT, i.e., DNATTα/β/γ/δ, was engineered to form a sensor circuitry, in which a target-specific monolayer of thiolated DNATTγ pinned down the analyte jointly with the reciprocal DNATTδ into a sandwich complex; the latter further rallied an in situ interdigital relay of biotinylated DNATTα/β into a microsized hyperlink dubbed polyDNATT. Its scale and growth factors were illuminated rudimentarily in transmission electron microscopy and confocal laser scanning microscopy. Using a nonsmall-cell lung cancer-related microRNA (hsa-miR-193a-3p) as the subject, a compound DNA-backboned construct was synthesized, fusing all building blocks together. Its superb tacticity and stereochemical conformality avail the templating of a horseradish peroxidase train, which boosted the paralleled catalytic surge of proton donors, resulting in an attomolar detection limit and a broad calibration range of more than seven orders of magnitude. Such oligomerization bested the conventional hybridization chain reaction laddering at both biomechanical stability and stoichiometric congruency. More significantly, it demonstrates the flexibility of DNA architectures and their multitasking ability in biosensing.

Being announced as one of the "2019 Top Ten Emerging Technologies in Chemistry" by IUPAC, the directed evolution of artificial metalloenzymes has led to a broad scope of abiotic processes. Here, inspired by those key proteins in bioluminescence, a rudimentary expression of bio-electrochemiluminescent (ECL) macromolecules was achieved via the complexation of zinc proto-porphyrin IX (ZnPPIX) within apo-hemoglobin (apo-Hb). A high-yield monochromic irradiation at 644 nm could be provoked potentiostatically from the reconstituted holo-HbZnPPIX in solutions. Its secondary structure integrity was elucidated by UV and circular dichroism spectrometry, while voltammetry-hyphenated surface plasmon resonance authenticated its ligation conservativeness in electrical fields. Further conjugation with streptavidin rendered a homogeneous Janus fusion of both receptor and reporter domains, enabling a new abiological catalyst-linked ECL bioassay. On the other hand, singular ZnPPIX inside each tetrameric subunit of Hb accomplished an overall signal amplification without the bother of luminogenic heterojunctions. This pH-tolerant and non-photobleaching optics was essentialized to be the unique configuration interaction between Zn and O2, by which the direct electrochemistry of proteins catalyzed the transient progression of O2 → O2·- → O2* + hυ selectively. Such principle was implemented as a signal-on strategy for the determination of a characteristic cancer biomarker, the vascular endothelial growth factor, resulting in competent performance at a low detection limit of 0.6 pg·mL-1 and a wide calibration range along with good stability and reliability in real practices. This simple mutation repurposed the O2-transport Hb in the erythrocytes of almost all vertebrates into a cluster of oxidoreductases with intrinsic ECL activity, which would enrich the chromophore library. More importantly, its genetically engineered variants may come in handy in biomedical diagnosis and visual electrophysiology.

In this study, CoFe2O4 is selected for the first time to synthesize CoFe2O4/Al nanothermite films via an integration of nano-Al with CoFe2O4 nanowires (NWs), which can be prepared through a facile hydrothermal-annealing route. The resulting nanothermite film demonstrates a homogeneous structure and an intense contact between the Al and CoFe2O4 NWs at the nanoscale. In addition, both thermal analysis and laser ignition test reveal the superb energetic performances of the prepared CoFe2O4/Al NWs nanothermite film. Within different thicknesses of nano-Al for the CoFe2O4/Al NWs nanothermite films investigated here, the maximum heat output has reached as great as 2100 J&middot, g&minus, 1 at the optimal thickness of 400 nm for deposited Al. Moreover, the fabrication strategy for CoFe2O4/Al NWs is also easy and suitable for diverse thermite systems based upon other composite metal oxides, such as MnCo2O4 and NiCo2O4. Importantly, this method has the featured advantages of simple operation and compatibility with microsystems, both of which may further facilitate potential applications for functional energetic chips.

Additional file 1: Table S1. List of the gene symbols of the 422 genes targetable by the enrichment panel. Figure S1. The presence of 134/144 bp dominant samples was independent of the tumor cfDNA purity. (A) cfDNA size ratios (100–150 bp/163–169 bp) showed poor correlation with the second high MSAF within the 35,134/144 bp dominant and the 35,166 bp dominant cfDNA samples. (B) cfDNA size ratios (100–150 bp/163–169 bp) showed poor correlation with the third high MSAF within the 35,134/144 bp dominant and the 35,166 bp dominant cfDNA samples. Spearman correlation ρ was labeled on the top right corner of each figure. Figure S2. Fragment size distribution of cfDNA at the TSS of unexpressed genes and house-keeping genes. The insert size distribution of cfDNA whole genome sequencing results was obtained using a publicly available dataset [1]. The 2000 bp region centered around the TSS of 3717 house-keeping genes and 325 unexpressed genes (as determined by the FANTOM5 project) were examined. All samples were combined. Figure S3. The size ratio of cfDNA at the TSS of genes classified based on their FPKM values. The left panel showed the boxplot of the size ratio (100–150 bp reads/163–169 bp reads) of cfDNA (lung cancer patient P2, SRX1921680) mapped to the 2000 bp region centered at the TSSs of genes with different expression levels according to lung cancer cell line A549. The right panel showed the boxplot of the size ratio of cfDNA (a healthy control, SRX1120814 [1]) mapped to the 2000 bp region centered on the TSSs of genes with different expression levels according to bone marrow tissue (downloaded from http://www.proteinatlas.org/about/download ). Figure S4. The size ratio of cfDNA mapped to DHS sites with different DHS score. This graph shows a boxplot of the size ratio of cfDNA based on WGS data obtained from a publicly available dataset [1]. The size ratio of each DHS site was grouped based on DHS signal intensity (as determined by the ENCODE project). DHS sites with a log2 transformed signal score less than 5 were excluded from this analysis. Each patient sample was matched to a cell line derived from the tissue type same as the patient’s primary tumor site, or to GM12878 when DNase-Seq result of such cell line is not available. cfDNAs extracted from healthy controls were matched to the DHS signal intensity of GM12878. Figure S5. Fragment size distribution of cfDNA from patient P2 mapped to H3K4me3 and H3K9me3 CHIP sites of A549. CHIP-seq data of H3K4me3 and H3K9me3 modification of lung cancer cell line A549 was obtained from the ENCODE project. This graph demonstrates the WGS result of cfDNA extracted from lung cancer patient P2 (SRX1921680) in our dataset. Figure S6. Fragment size distribution of cfDNA mapped to H3K4me3 and H3K9me3 CHIP sites of GM18535. CHIP-seq data of H3K4me3 and H3K9me3 modification of normal lymphocyte cell line GM18535 was obtained from the ENCODE project. This graph demonstrates the whole genome sequencing result of cfDNA extracted from a healthy control (SRX1120814 [1]). Figure S7. cfDNA shortening to the 134/144 bp dominant state was a global event. (A) CNV profile of a 134/144 bp dominant cfDNA sample (SRX1921679). The log2 fold change in each 100 k bp consecutive non-overlapping window was plotted. The sample was collected from a female patient with stage IV lung cancer. The grey horizontal dashed line (log2 fold change = 0) labeled the normal copy number state. (B) Size ratio profile of the 134/144 bp dominant cfDNA sample (SRX1921679). The size ratio in each 1000 bp consecutive non-overlapping window was calculated and plotted. Red data points highlighted the regions of the top 100 highest size ratios. Blue data points highlighted the regions of 100 lowest size ratios. The grey horizontal dashed line marked size ratio = 4, which is a threshold to separate the 134/144 bp dominant samples from 166 bp dominant samples. Figure S8. Endpoints of short fragment cfDNA around the TSS regions. (A) Frequencies of 5′ endpoint of the fragments (51–60 bp, 61–70 bp, 71–80 bp, 81–90 bp, and 91–100 bp) in consecutive non-overlapping 5 bp windows within − 300 to 500 bp of the TSS. (B) Frequencies of 3′ endpoint of the fragments (51–60 bp, 61–70 bp, 71–80 bp, 81–90 bp, and 91–100 bp) in consecutive non-overlapping 5 bp windows within − 300 to 500 bp of the TSS. In each graph, vertical dashed lines marked the positions of the first peak downstream of TSS of the curves as fitted using locally weighted scatterplot smoothing (LOWESS).

NiCo2O4 has been selected as an oxidizer to realize the nanothermite film for the first time in this study. The NiCo2O4/Al core-shell nanowires (NWs) thermite film has been fabricated using a facile hydrothermal-annealing synthesis method and a controllable magnetron sputtering process. The as-obtained NiCo2O4/Al NWs thermite film shows a uniform structure and distribution on the substrate, with a favorable interfacial contact between the bimetallic oxide and the fuel at the nanoscale. It is found that the quantity of Al plays a key role in the total heat release magnitude. The maximal heat release of the NiCo2O4/Al nanothermite film has reached 2076.0 J/g at the optimal Al deposited thickness of 450 nm with the obtained optimum Al/NiCo2O4 molar ratio of 4.9. Moreover, this design strategy is highly compatible with microelectromechanical systems (MEMs) and it can be applied to realize other nanothermites composed by bimetallic oxide and fuel. Keywords: NiCo2O4/Al, Core-shell nanowires structure, Nanothermite film, Heat release, Magnetron sputtering

In this work, a biosensor for ultrasensitive detection of glucose via electrochemically mediated atom transfer radical polymerization (eATRP) was firstly reported in the field of biosensing analysis. Firstly, 4-mercaptophenylboronic acid was immobilized onto Au electrode surface via Au S bond to recognize glucose by producing 5-membered cyclic boronic ester. Then initiators of atom transfer radical polymerization were introduced to the electrode surface by the reaction between 2-bromoisobutyryl bromide and the remaining hydroxyl groups of glucose to produce the alkyl halide initiation site. The monomer began to graft onto the electrode surface, and an electrochemical potential was applied to activate the copper catalyst for the formation of polymeric chains which were labeled numerous electroactive probes ferrocene. The square wave voltammetry was applied to monitor electrochemical signal of quantitatively labeled ferrocene. Under optimal conditions, this strategy for ultrasensitive detection of glucose presented a good linear relationship between oxidation current of ferrocene and logarithm of glucose concentrations in the range from 1.0 nM to 10 μM with an extremely low limit of detection of 0.32 nM (R2 = 0.996). In addition, this strategy showed good specificity for glucose detection in physiological conditions and also showed high reliability in human serum.

In order to investigate the catalytic activity of nano-MnO2 on the thermal decomposition of ammonium perchlorate, two different shapes of nano-MnO2 (sea-urchin and linear) were prepared by the hydrothermal method with MnSO 4·H2O and Na2S2O8, MnSO4·H2O and (NH4)2S2O8 , respectively. X-ray diffraction , scanning electron microscopy and the nitrogen adsorption/desorption analysis were used to characterize the structure of the nanocomposites. The sea-urchin nano-MnO 2 possesses a greater specific surface area than the linear nano-MnO2. The catalytic properties of nano-MnO2 on the thermal decomposition of ammonium perchlorate (AP) were demonstrated by differential scanning calorimeter (DSC). As show in the DSC carves, the addition of the sea-urchin nano-MnO2 got the thermal decomposition peak temperature of AP reduced much more than the addition of the linear nano-MnO2, the low-temperature decomposition process even disappeared, and the high-temperature pyrolysis peak temperature decreased by 94.6 °C. All evidences indicated that the sea-urchin nano-MnO2 is a better catalytic than the linear one.

The energy performance of nanothermites in aqueous conditions is commonly restricted by the rapid heat dissipation and corrosion of nano-Al. Here we report studies on the fabrication and submerged ignition for the super-hydrophobic nanothermite film based upon the Co3O4/Al core/shell nanowires (NWs). The Co3O4 NWs arrays, which are synthesized using a facile hydrothermal-annealing method, serve as templates for the deposition of Al shells by magnetron sputtering. The super-hydrophobic surface is subsequently realized by the fluoroalkylsilane coating. The tests of the laser-induced underwater ignition reveal that the super-hydrophobic modification effectively could lead to the ignition of the nanothermite film. Furthermore, the anti-aging behaviors of the obtained super-hydrophobic nanothermite film in aqueous conditions are investigated in detail to compare the heat-release and ignition characteristics at different submersion times. Impressively, the resultant super-hydrophobic composite could still hold about 50% of the original energy even after an underwater storage of 2 days.

It is found for the first time that ferrocene (Fc) can be used as a peroxidase mimic to catalyze the oxidation of hydrogen peroxide (H2O2) in this experiment. Hydroxyl radicals (OH˙), one product from oxidation reactions, oxidizes TMB (colorless solution) to TMBOX (blue solution). Double-reciprocal plots present that the catalysis mechanism of Fc in H2O2 oxidation is consistent with the ping-pong mechanism. Additionally, Fc was successfully utilized for polyaniline (PANI) microsphere synthesis in the presence of H2O2. Compared with the control, better physical and chemical properties of PANI synthesized in the presence of Fc are found in this study.

Co 3 O 4 nanowires (NWs) arrays were successfully fabricated via a facile hydrothermal-annealing method. The component, structure and morphology of the Co 3 O 4 NWs arrays were characterized. The slim Co 3 O 4 NWs consist of interconnected nanocrystals and have a specific surface area of 26.6 m 2 g −1 . The obtained materials have exhibited an excellent catalytic performance on the thermal decomposition of ammonium perchlorate (AP). In addition, catalytic activities of the prepared Co 3 O 4 mainly depend on the content of catalyst. Impressively, an addition of 9 wt% Co 3 O 4 NWs arrays to AP exhibited the most significant catalytic effect in lowering the decomposition temperature from 404 to 288 °C, increasing the decomposition heat from 502 to 930 J g −1 and decreasing the activation energy from 201 to 168 kJ mol −1 . Furthermore, the catalytic mechanism of the Co 3 O 4 NWs arrays based on electron transfer processes was discussed.

In this study, the three-dimensional ordered macroporous (3DOM) structure is applied to the preparation of the core-shell structure metal matrix composites. 3DOM Fe2O3, which was coated with different molar ratios of Co3O4, was successfully synthesized by inversing PS spheres colloidal crystal template and sol-gel methods, and subsequently characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 absorption-desorption isotherms, X-ray diffraction (XRD). The catalytic activities of 3DOM Fe2O3/xCo3O4 core-shell composites, 3DOM Fe2O3, bulk Fe2O3 and bulk Fe2O3/Co3O4 on the thermal decomposition of ammonium perchlorate (AP) were investigated by differential scanning calorimeter (DSC). The results indicated that all products showed excellent catalytic activity. Among the samples investigated here, the 3DOM Fe2O3/0.70Co3O4 exhibited the best catalytic activity, since the maximum peak temperature for the decomposition of the AP decrease to 308.5 °C. The enhanced catalytic performance of 3DOM Fe2O3/0.70Co3O4 was attributed to its unique porous architecture, high surface area, Fe2O3-Co3O4 heterojunction and good adsorption capacity. Hence, 3DOM Fe2O3/0.70Co3O4 was expected to be used as the promising catalysts in modifying the burning performance of AP-based composite propellant.

Surface ozone, NO, NO2, and NOx were measured at a coastal site (Shihua) and a nearby inland site (Zhujing) in suburban Shanghai for the whole year of 2009. More days with ozone pollution in a longer time range were observed at the coastal site than the inland site. The diurnal variations of NOx concentrations were obviously higher at Zhujing station, while those of ozone concentrations were higher at Shihua station, indicating their different air pollution conditions. Coastal wind has significant influence on the levels and characteristics of the air pollutants. The ozone concentrations during maritime winds (MW) were much higher than those during continental winds (CW) at each of the site, while the NO and NO2 concentrations were both opposite. The ozone concentrations at Shihua station were much higher than those at Zhujing station, while the NO and NO2 concentrations were both opposite. The ozone concentrations at both of the two sites showed a distinct “weekend effects” and “weekdays effects” patterns during CW and MW, respectively. Correlation analysis of the pollutants showed that, the compounds during MW were more age than those during CW, and the compounds at Shihua were more age than those at Zhujing. The air pollutions at both of the two sites are mainly associated with the pollutants emitted in this region instead of long range transport.

In this work, pyrrolidyl C60 derivative was recruited as an unadulterated and congruent nano-hub to converge three zinc porphyrins on its monopole. Such peculiar assembly was convinced via micro-imaging and spectrophotometry. Making the best of fullerenyl proficiency in catalytic singlet O2 generation and excited-state preservation, a multiplied electrochemiluminescence (ECL) emission bursted out from the porphyrin trinity in a synergistic manner. Without any prebio-conjugation, this orderly ECL-active individual turned to anchor in the toroid of a peripherally modified gamma-cyclodextrin in a good shape match. From the facile direct mounting of the latter derives a universal bio-probing technique based upon such host-guest inclusion. Its binding pattern and the concomitant effects on interfacial properties were revealed by systematic process characterizations. Taking advantages of this uniform ensemble in both size and stoichiometry, an in situ terminal labelling strategy during the recognition-induced allosteric event came into being, which managed a neat signal enhancement for the detection of model miRNA marker. Even in real samples, the developed sensing approach could achieve high precision, comparable sensitivity and satisfactory selectivity. The adaptation of macrocyclic chemistry for refined biotransducers and efficient ECL amplifiers would offer a generic and potent alternative to the analyte-specified ECL indicator-receptor build in bioassays.

The compatible catalytic structure of NiCo

Ultrasensitive electrochemiluminescence (ECL) detection can benefit substantially from the rational configuration of emitter−enhancer stereochemistry. Here, using zinc(II) meso-5,10,15,20-tetra(4-sulfonatophenyl)porphyrin (ZnTSPP) as a model, we demonstrate that both the ECL intensity and the photostability of this emitter were significantly improved when it was trapped in pyridyl-bridged β-cyclodextrin dimer (Py(CD)2); a synthetic enhancer that is ECL inactive. Through NMR characterization, we confirmed that ZnTSPP formed a clam-like inclusion complex involving pinning and pinching forces from the biocompatible container Py(CD)2. Up to a threefold increase in the ECL brightness of ZnTSPP was witnessed when it was encapsulated in β-CD. Absorption and emission spectroscopic data revealed that both the extended excitation lifetime and the restricted mobility of the guest contributed to the observed improvement in signal transduction within the host molecule. This bioinspired entrapment also led to a marked boost in ECL stability. With the aid of the newly identified coreactant H2O2, the hollow TSPP@Py(CD)2 system was employed to create a Zn2+-selective probe that was capable of sensitive and accurate zinc detection. The observed increase in ECL conversion and enhanced photophysical properties of this compact supramolecular assembly render it a novel template for enhancing ECL in analytical applications.

The development of nanothermites with adjustable reactivity has always been the research hotspot in the field of energetic materials, and its key issue is to control the interfacial contact extent and diffusion length between fuel and oxidizer. Here, the 3DOM CuO/Al, 3DOM CuO/Al-NPs and CuO-NPs/Al-NPs nanothermites, which show a gradual decrease in contact extents between reactants, were firstly prepared simultaneously using magnetron sputtering, P4VP self-assembly and ultrasonic mixing, respectively. The DSC thermograms show that the heat release of the 3DOM CuO/Al (sputtering 200 nm Al) can reach 2541.4 J/g, much larger than either value of the prepared 3DOM CuO/Al-NPs and CuO-NPs/Al-NPs. The activation energies of these CuO/Al systems also exhibit the similar results as the heat releases. However, the 3DOM CuO/Al-NPs can lead to the highest combustion pressure (24.6 MPa), the shortest pressure rise time (0.067 ms), and the fastest pressurization rate (647.98 GPa/s), followed orderly in corresponding values by the CuO-NPs/Al-NPs and 3DOM CuO/Al. All data indicate that the contact extent between CuO and Al plays a great effect on the overall reactivity, and their differences in structure and volume are responsible for the diverse combustion pressure performance. Furthermore, the presence of reaction voids between components can promote the O diffusion to enhance the continuous mass and heat transfer for an efficacious reaction. Hence, it is believed that similar methods can be used to improve the contact extent and diffusion length between fuels and oxidants so as to achieve an adjustment in reactivity for various nanothermites.

The huge energy release and highly adjustable combustion characteristics of nanoporous silicon (nPS) make it one of the most attractive inorganic energetic materials. However, nPS will be oxidized slowly from its surface when it is left in ambient air to be aged. Explanations vary as to the aging mechanism, and the corresponding anti-ageing strategy remains to be fully investigated. The present study provides an efficient strategy of a thermal-induced hydrosilylation to improve the long-term chemical stability of H-terminated nPS. The nPS of 75 μm in depth was etched with a pore diameter of 52.5 nm and a gravimetry-determined porosity of 79.6%. The DSC and FTIR data confirm that oxygen is able to infiltrate the H-terminated layer and preferentially attack the weak Si-Si over Si-H bonds. The prime oxidizer is not sodium perchlorate but oxygen from the air to cause a backbond oxidation. After a modification, the heat of reaction is determined to be 1436 J·g−1. Interestingly, this value is of almost no detectable change to be 1402 J·g−1 and 1387 J·g−1 when aged for 24 or 48 h, respectively. All the evidences suggest that the alkyl-terminated nPS exhibits an excellent anti-oxidation ability to ambient air, which is well consistent with a high-speed video analysis from the combustion behavior of nPS impregnated with NaClO4·H2O. This work suggests that only one step may be away from a practical application of nPS energetic materials.

The article describes an on-chip amplification scheme initiated by a terminal deoxynucleotidyl transferase (TdT) for highly sensitive fluorometric determination of protein. Two thrombin-binding aptamers were designed to capture thrombin as they can form a sandwich structure for improved specificity. An amino-modified aptamer (TBA29) was first immobilized on a silicon chip. After capture of thrombin, a second aptamer (TBA15) was conjugated to the second binding site of thrombin. The 3'-terminal of aptamer TBA15 is exposed on the chip surface, and then fluorescein-labeled 12-dATP associates to the 3'-terminal with the help of TdT. This results in signal amplification, and eventually leads to highly sensitive detection. Under optimal conditions, fluorescence intensity is linearly related to the logarithm of thrombin concentration in the range of 100 fM - 0.1 μM, and the detection limit is as low as 2.0 fM. The assay is sensitive and selective even over potentially interfering proteins and in the presence of human serum. Graphical abstract Schematic strategy for thrombin detection. Two thrombin-binding aptamers were designed to capture thrombin to form a sandwich structure for improved specificity. The protein detection is based on TdT initiated on-chip fluorescent amplification.

In this study, a new method was reported for the fabrication of the nanostructured CuO/Al thermite film on a Cu substrate. The CuO nanorod (NR) arrays grew vertically from the Cu surfaces by electrochemical anodization processes, followed by the deposition of an Al layer on the CuO NRs via magnetron sputtering to form a core/shell CuO/Al nanothermite film, whose component, structure and morphology were subsequently characterized. In addition, the energy-release characteristics of the obtained nanothermite film were investigated using thermal analyses and laser ignition tests. All evidence demonstrates that the obtained CuO/Al is of a uniform structure and has superb energy performance. Impressively, the resulting material is potentially useful in applications of functional energetic chips due to its easy integration with microelectromechanical systems (MEMS) technologies.

Microigniters play an important role for the reliable initiation of micro explosive devices. However, the microigniter is still limited by the low out-put energy to realize high reliability and safety. Integration of energetic materials with microigniters is an effective method to enhance the ignition ability. In this work, a Al/Co3O4 nanothermite film with a three-dimensionally ordered macroporous structure was prepared by the deposition of nanoscale Al layers using magnetron sputtering on Co3O4 skeletons that are synthesized using an inverse template method. Both the uniform structure and nanoscale contact between the Al layers and the Co3O4 skeletons lead to an excellent exothermicity. In order to investigate the ignition properties, a micro-energetic igniter has been fabricated by the integration of the Al/Co3O4 nanothermite film with a semiconductor bridge microigniter. The thermite reactions between the nanoscale Al layer and the Co3O4 skeleton extensively promote the intensity of the spark, the length in duration and the size of the area, which greatly enhance the ignition reliability of the micro-energetic igniter. Moreover, this novel design enables the micro-energetic igniter to fire the pyrotechnic Zr/Pb3O4 in a gap of 3.7 mm by capacitor discharge stimulation and to keep the intrinsic instantaneity high and firing energy low. The realization of gap ignition will surely improve the safety level of initiating systems and have a significant impact on the design and application of explosive devices.

The aim of this retrospective study was to evaluate the prognostic influence of lymphatic vessel invasion (LVI) in stage I non-small cell lung cancer (NSCLC) patients. From January 2004 to December 2007, LVI was detected in 57 patients with T1N0M0 NSCLC; therefore, 114 patients with the same pathology, T stage, and surgery method, but without LVI, were selected as the control group to compare survival. The overall survival and relapse-free survival rates were estimated using the Kaplan-Meier method, log-rank test, and Cox proportional hazards analysis. The average follow-up length was 59.94 ± 23.1 months. The 5-year overall survival rates of the LVI-negative and the LVI-positive groups were 90.54 and 70.1%, respectively (P = 0.002). A multivariate analysis revealed LVI to be an independent predictive factor (hazard ratio = 4.562; P = 0.004). The 5-year overall survival rates for patients who received postoperative adjunctive therapy and those who did not in the LVI-positive group were 88.2 and 61.5%, respectively, with a P value less than 0.05 in both univariate and multivariate analyses. LVI is a poor prognostic factor in stage I NSCLC patients; postoperative adjunctive therapy is needed to improve the prognosis of NSCLC patients with LVI.

Microigniters play an important role for the reliable initiation of micro explosive devices. However, the microigniter is still limited by the low out-put energy to realize high reliability and safety. Integration of energetic materials with microigniters is an effective method to enhance the ignition ability. In this work, a Al/Co

In this work, we report a novel use of the distinctive metal-to-ligand charge-transfer (MLCT) absorption properties of the chromogenic Fe(BPDS)34- (BPDS=bathophenanthroline disulfonic acid) reporter for the visual detection of β-galactosidase (β-Gal) activity and sandwich immunoassay. The enzymatic hydrolysis of the substrate p-aminophenyl-β-D-galactopyranoside can switch on the reduction of Fe3+ to Fe2+ and the subsequent complexation of Fe2+ with the BPDS ligand to generate the Fe(BPDS)34- reporter, leading to the appearance of the intense MLCT absorption band at 535nm and the colorless-to-red color change of the solution. Simply through a single step, the activity of β-Gal can be sensitively and selectively detected within the dynamic range of 0-220mUmL-1, with a limit of detection (LOD) of 1.69mUmL-1. This approach is applicable for the visual detection of β-Gal activities in the presence of complex human serum samples. Besides, when integrated with the sandwich immunoassay of carcinoembryonic antigen, a LOD of 1.16ngmL-1 can be achieved. In light of its prominent simplicity and practicality, our MLCT-based approach holds great potential in diagnostic and analytical applications.