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The electrochemical corrosion behavior of the dental Ti50Zr alloy with and without nanocrystalline (TiZr)N coating was comparatively investigated in artificial saliva solutions with different pH values and fluoride ion concentrations. The chemical stability of the passive films on the coated and non-coated Ti50Zr alloy was evaluated by calculating passive film thickness. The chemical compositions and valence structures of the passive films were analyzed by X-ray photoelectron spectroscopy (XPS). The results show that the (TiZr)N-coated alloy displays distinctly decreased corrosion rate and increased impedance compared with Ti50Zr alloy in non-fluoridated and fluoridated acidic solutions. Particularly, in the solution of pH = 3.9 and 0.15% NaF-containing, the corrosion protection efficiency of (TiZr)N coating reaches 90%. The excellent corrosion resistance of the coated alloy is attributed to that the nanocrystallines in (TiZr)N coating decreases micropores and crack defects, which strongly impedes the corrosive ions diffusion and electrode process at Ti substrate/coating interface. Meanwhile, (TiZr)N coating shows good passivation behavior in acidic solution and active–passive transition behavior in fluoridated acidic solution. The coated Ti50Zr alloy with high chemical stability has potential application prospect for dental implants.

Herein, a facial stratagem for the large-scale synthesis of NiO/C nanosheets used as magnetic adsorbents is proposed by using nanoscale coordination polymers (nanoCPs) as precursors. The NiO nanoparticles (NPs) scattered on the NiO/C nanosheets have an untrasmall size (~3 nm) as well as uniform dispersion, since the Ni2+ ions are preassembled into the nanoCPs precursors by coordination bonds and transformed to NiO NPs in situ under the restriction of carbon layers. Thanks to the small size and spatially uniform distribution of NiO NPs, fully exposed carbon matrix containing part of graphene structures, and the high specific surface area of the special nanosheet structure, the magnetic NiO/C nanosheets have an a great breakthrough in the adsorption performance toward Congo Red (CR) among many reported NiO-based materials. The maximum adsorption capacity for CR is up to 2000 mg/g, and the adsorption kinetics and thermodynamics are also systematically studied. Moreover, the NiO/C nanosheets can be separated from water and reused simply by an external magnetic field. The NiO/C nanosheets with low cost and extraordinary adsorption ability have great potential in water pollution treatment area.

Based on green chemistry, 3D hierarchical ZnO microflowers (MFs) constructed from layered 2D nanosheets have been designed as carriers to uniformly load PdO/Pd nanoparticles by the calcination of the precursor (ZnO/Pd(II) microflowers) in air. The ZnO/Pd(II) microflowers are prepared by dipping the 3D ZnO MFs in an ethanolic solution of PdCl2 without involving additional agents. The as-prepared 3D hierarchical ZnO microflowers are a stable support to enhance the dispersibility of PdO/Pd nanoparticles to achieve better catalytic performance for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). In addition, the synergistic effect between the PdO and Pd nanoparticles is another major driver that promotes the catalytic process. Over 98% of 4-NP is reduced within 7 min. Furthermore, structural analysis of the ZnO/PdO/Pd microflowers can provide useful information for understanding structure-performance relationships.

Rationale: Malignant ascites caused by cancer cells results in poor prognosis and short average survival time. No effective treatment is currently available for malignant ascites. In this study, the effects of lentinan (LNT)-functionalized selenium nanoparticles (Selene) on malignant ascites were evaluated. Furthermore, the mechanism of Selene targeting mitochondria of tumor cells were also investigated. Methods: Selene were synthesized and characterized by TEM, AFM and particle size analysis. The OVCAR-3 and EAC cells induced ascites models were used to evaluate the effects of Selene on malignant ascites. Proteomic analysis, immunofluorescence, TEM and ICP-MS were used to determine the location of Selene in tumor cells. Mitochondrial membrane potential, ROS, ATP content, and caspase-1/3 activity were detected to evaluate the effect of Selene on mitochondrial function and cell apoptosis. Immunofluorescence, Co-IP, pull-down, duolink, Western blot, and FPLC were used to investigate the pathway of Selene targeting mitochondria. Results: Selene could effectively inhibit ascites induced by OVCAR-3 and EAC cells. Selene was mainly located in the mitochondria of tumor cells and induced apoptosis of tumor cells. The LNT in Selene was involved in caveolae-mediated endocytosis through the interaction between toll-like receptor-4 (TLR4) and caveolin 1 (CAV1). Furthermore, the Selene in the endocytic vesicles could enter the mitochondria via the mitochondrial membrane fusion pathway, which was mediated by TLR4/TNF receptor associated factor 3 (TRAF3)/mitofusin-1 (MFN1) protein complex. Conclusion: Selene is a candidate anticancer drug for the treatment of malignant ascites. And TLR4/TRAF3/MFN1 may be a specific nano-drug delivery pathway that could target the mitochondria.

A novel supercapacitor material was synthesized from SiO2-coated Co3O4 and CuO nanoparticles. These nanocapsules provided large specific surface area, fast electron transport, good mechanical stability and high electrochemical activity. The specific capacitance at 1 A g−1 was 835.4 F g−1, and it had excellent cycling performance.

We designed a facile and green self-assembly route for the large-scale production of bimetallic coordination polymer–Zn(MAA)2/Pd(II) nanoribbons by employing two terminal units with distinct hard–soft properties of the smallest semi-rigid methacrylate anion (MAA−) to combine with two different metal ions. The COO− (chemically hard base) served as the initial unit, which was applied to coordinate with the Zn2+ ions for constructing the host network of this Janus CPs by facilely adjusting the proportion of ethanol/water to control the degree of solvation. After soaking in an ethanol solution of PdCl2, the alkene units (chemically soft base) act as secondary donors to load the soft noble metal Pd2+ ions and form Zn(MAA)2/Pd(II) nanoribbons, which are ideal precursors of ZnO/PdO nanoribbons. By pyrolyzing the dual metal ion equipped Zn(MAA)2/Pd(II) precursors, ZnO nanoribbon supported PdO nanoparticles (NPs) with a well-defined structure were facilely fabricated on a large scale. Furthermore, the as-obtained ZnO/PdO nanoribbons exhibit efficient catalytic performance for the reduction of 4-NP, which can convert 99.3% of the substrates within 6 min. This superior catalytic performance may be attributed to the well-dispersed PdO nanoparticles as well as the absence of additional agents introduced a green synthetic method.

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor, and almost half of the patients carrying EGFR-driven tumor with PTEN deficiency are resistant to EGFR-targeted therapy. EGFR amplification and/or mutation is reported in various epithelial tumors. This series of studies aimed to identify a potent compound against EGFR-driven tumor. We screened a chemical library containing over 600 individual compounds purified from Traditional Chinese Medicine against GBM cells with EGFR amplification and found that cinobufagin, the major active ingredient of Chansu, inhibited the proliferation of EGFR amplified GBM cells and PTEN deficiency enhanced its anti-proliferation effects. Cinobufagin also strongly inhibited the proliferation of carcinoma cell lines with wild-type or mutant EGFR expression. In contrast, the compound only weakly inhibited the proliferation of cancer cells with low or without EGFR expression. Cinobufagin blocked EGFR phosphorylation and its downstream signaling, which additionally induced apoptosis and cytotoxicity in EGFR amplified cancer cells. In vivo, cinobufagin blocked EGFR signaling, inhibited cell proliferation, and elicited apoptosis, thereby suppressing tumor growth in both subcutaneous and intracranial U87MG-EGFR xenograft mouse models and increasing the median survival of nude mice bearing intracranial U87MG-EGFR tumors. Cinobufagin is a potential therapeutic agent for treating malignant glioma and other human cancers expressing EGFR.

Repulsive guidance molecule A (RGMa) is a potent inhibitor of axonal growth and a regulator of neuronal cell death. It is up-regulated following neuronal injury and accumulates in chronic neurodegenerative diseases. Neutralizing RGMa has the potential to promote neuroregeneration and neuroprotection. Previously we reported that a rat anti-N terminal RGMa (N-RGMa) antibody r5F9 and its humanized version h5F9 (ABT-207) promote neuroprotection and neuroregeneration in preclinical neurodegenerative disease models. However, due to its cross-reactivity to RGMc/hemojuvelin, ABT-207 causes iron accumulation in vivo, which could present a safety liability. Here we report the generation and characterization of a novel RGMa-selective anti-N-RGMa antibody elezanumab, which is currently under Phase 2 clinical evaluation in multiple disease indications. Elezanumab, a human monoclonal antibody generated by in vitro PROfusion mRNA display technology, competes with ABT-207 in binding to N-RGMa but lacks RGMc cross-reactivity with no impact on iron metabolism. It neutralizes repulsive activity of soluble RGMa in vitro and blocks membrane RGMa mediated BMP signaling. In the optic nerve crush and optic neuritis models, elezanumab promotes axonal regeneration and prevents retinal nerve fiber layer degeneration. In the spinal targeted experimental autoimmune encephalomyelitis (EAE) model, elezanumab promotes axonal regeneration and remyelination, decreases inflammatory lesion area and improves functional recovery. Finally, in the mouse cuprizone model, elezanumab reduces demyelination, which is consistent with its inhibitory effect on BMP signaling. Taken together, these preclinical data demonstrate that elezanumab has neuroregenerative and neuroprotective activities without impact on iron metabolism, thus providing a compelling rationale for its clinical development in neurodegenerative diseases.

Carcinoembryonic antigen (CEA) is an important malign tumor marker. In this study, a simple, label-free and antibody-free aptasensor was fabricated based on a multifunctional dendrimer-like DNA nanoassembly. The DNA nanoassembly was embedded with multiple G-quadruplex DNAzyme motifs and a hanging CEA aptamer motif. It was prepared from short DNA sequences by autonomous-assembly. The aptasensor was prepared simply by self-assembly of a capture DNA (cpDNA) on a gold electrode, followed by hybridization with a CEA aptamer (AptGAC-P). CEA as a model target was detected through competitive binding of CEA with AptGAC-P, exposing cpDNA to bind with the DNA nanoassembly. The detection process only contains 2 incubation steps. The high load of G-quadruplex DNAzyme motifs and their catalytic activity resulted in an amplified and label-free differential pulse voltammetry (DPV) electrochemical signal. The peak current correlated linearly with the CEA concentration, with a linear range of 2–45 ng mL−1, and an LOD value of 0.24 ng mL−1. The aptasensor showed high specificity and reproducibility, and retained 96.5% of detection signal intensities after 31 days of storage. The recovery rates for spiked CEA in human serum were within 100 ± 5%, and the coincidence rates for clinical human serum samples with ELISA kits were 80.7–111%. Conceivably, possessing simplicity, sensitivity, reproducibility, storage stability, and accuracy, the aptasensor should be a very prominent and applicable tool for clinical CEA detection and cancer diagnosis, and is promisingly applicable as a platform for detecting other targets of interests.

Large-scale Ni-based nano-sized coordination polymers (Ni-nCPs) are facilely constructed by a self-assembled approach at room temperature and atmosphere pressure. In this strategy, we use only the environmentally friendly solvents of water and ethanol, and the synthesis of 2D Ni-nCPs via a self-assembly route appears close to the “green chemistry” concept. In addition, the morphologies of the Ni-nCPs can be easily adjusted by the water/ethanol ratio. Owing to its unique 2D ultrathin nature and large specific surface area, Ni-nCPs-1 achieves a great number of channels for the transport of electrons and ions and electrochemically redox active sites for a faradaic reaction. Therefore, battery-type Ni-nCPs-1 electrodes have a bright prospect in energy storage, and can reach an outstanding specific capacitance value as high as 1066.9 F g−1 at 1 A g−1. Additionally, the asymmetric supercapacitor (Ni-nCPs-1//active carbon) displays a high energy density of 47.9 W h kg−1 at a power density of 440 W kg−1 and an excellent long-term cycle stability. This work may open up a new path in advanced electrode materials for efficient and real-time energy storge applications.

The photoionization of helium ion in bichromatic circularly polarized XUV laser pulses is investigated by solving the time-dependent Schrӧdinger equation. It shows that the electron can reach the continuum at the same momentum by absorbing one high-energetic photon or two low-energetic photons sequentially, and these two pathways can interfere with each other. Moreover, the interference can induce the asymmetrical round and the spiral-loop photoelectron momentum distributions in bichromatic circularly laser fields without and with the time delay.

A nanocrystalline TiN graded coating was prepared on Ti6Al4V alloy by DC reactive magnetron sputtering method. The microstructure and mechanic properties of the coating were investigated. The electrochemical corrosion and tribocorrosion of the coated specimens in physiological environment were compared with those of Ti6Al4V substrate. The results show that the gradient distribution of nanocrystalline TiN is favorable for releasing the inner stress in the coating, which increases adhesion strength to 90 N. The compact structure and refined-grains of the coating result in the surface nanohardness of 28.5 GPa. The corrosion protection efficiency of the nanocrystalline TiN coating reaches 96.6%. The tribocorrosion resistance of the coating increases by 100 times in comparison with that of Ti6Al4V substrate. The high chemical stability and H3/E2 ratio (where H is hardness, and E is elastic modulus) of the nanocrystalline TiN coating are responsible for good corrosion and wear resistances.

DNA aptamers against carcinoembryonic antigen (CEA) have been identified through the systematic evolution of ligands by exponential enrichment (SELEX) technique, but their affinity needs to be improved. In this study, an in silico approach was firstly used to screen the mutation sequences of a reported DNA aptamer (the parent aptamer, denoted as P) against CEA. The affinities of several high-score DNA mutants were determined by the biolayer interferometry technique. Finally, the newly obtained aptamers were verified in an aptasensor application. For the in silico approach, Mfold and RNA Composer were combined to generate the 3D RNA structures of the DNA mutants. The RNA structures were then modified to 3D DNA structures with the Write program. The docking model and binding ability of the 3D DNA structures with CEA were simulated and predicted with the ZDOCK program. Two mutation sequences (P-ATG and GAC-P) exhibited significantly higher ZDOCK scores than P. The dissociation constant of P-ATG and GAC-P to CEA was determined to be 4.62 and 3.93 nM respectively, obviously superior to that of P (6.95 nM). The detection limit of the P-ATG and GAC-P based aptasensors was 1.5 and 1.2 ng mL−1, respectively, markedly better than that based on P (3.4 ng mL−1). The consistency between the in silico and the experimental results indicates that the developed in silico post-SELEX screening approach is feasible for improving DNA aptamers. The P-ATG and GAC-P aptamers found in this study could be used for future CEA aptasensor design and fabrication, promisingly applicable for highly sensitive CEA detection and early cancer diagnosis.

CuO nanoparticles (CuO NPs) with ultrasmall size (∼3.6 nm) and a highly-dispersed pattern embedded in a silica matrix were obtained in situ through a calcination process of organic copper salt. By means of rational selection of reactants, organic copper salt was introduced into Si–O–Si networks via covalent bonding during the sol–gel process under neutral conditions without any additional catalyst. The introduction of organic copper salt via covalent bonding as well as the compact Si–O–Si networks allowed for the formation of highly dispersed and ultrasmall sized CuO NPs. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the obtained silica complex had spherical morphology and well-dispersed small sized CuO NPs. The as-obtained CuO@SiO2 nanocomposites exhibited good catalytic property on the reduction of organic dye with NaBH4 as the reducing agent.

Background: Long non-coding RNA FGD5 antisense RNA 1 (FGD5-AS1), identified to be a carcinogenic lncRNA, exhibits a regulatory role in some malignancies including non-small cell lung cancer (NSCLC). The aim of the present research is to decipher the function and underlying mechanism of FGD5-AS1 in progression of NSCLC. Methods: Expression of FGD5-AS1, miR-493-5p and DEAD-box protein 5 (DDX5) in NSCLC tissues and cells was quantified utilizing qRT-PCR. Cell proliferation was assessed by CCK-8 method. Scratch healing test and Transwell assay were used for assaying cell migration and invasion. Expressions of DDX5 and epithelial-mesenchymal transition (EMT)-related proteins were examined by Western blot. Additionally, targeting relationships between FGD5-AS1 and miR-493-5p, miR-493-5p and DDX5 were verified by dual-luciferase reporter gene assay. Results: Expression of FGD5-AS1 in NSCLC tissues and cell lines was up-regulated. Expression of FGD5-AS1 was in association with enlarged tumor size and lymph node metastasis of the patients. Knockdown of FGD5-AS1 led to the inhibition of proliferation, migration, invasion and EMT of NSCLC cells. FGD5-AS1 directly targeted miR-493-5p, while DDX5 was the target of miR-493-5p in NSCLC cells. Additionally, FGD5-AS1 could positively regulate the expression of DDX5 via suppressing miR-493-5p. Conclusion: FGD5-AS1 facilitates the proliferation, migration, invasion and EMT of NSCLC cells by sponging miR-493-5p and up-regulating DDX5.

The development of high-efficiency metal oxide electrode materials with high reaction kinetics and excellent conductivity are a cutting-edge strategy to obtain high-performance energy storge devices. Forming oxygen vacancy on the surface of the metal oxide tune electronic structure is a feasible approach to boost the electroactive of metal oxides for supercapacitor. Herein, an effective solution reduction method is reported for tuning the electronic structure of Co3O4 nanoribbons reacting with NaBH4 to enhance the faradaic redox reaction for high electrochemical performance. The vacancy-rich defects can endow more electroactive sites and reduce the electrical resistance for the enhanced supercapacitor performance. Therefore, compared to pristine Co3O4 (347.4 F g-1), the reduced Co3O4 (R-Co3O4) shows a high specific capacitance (Cs, 464.9 F g-1) and a reduced charge transfer resistance. The asymmetric supercapacitor (ASC, R-Co3O4// active carbon) exhibits an energy density of 18.6 Wh kg-1 at the power density of 400 W kg-1 and excellent cycling stability. Such a feasible approach realizes the electronic tuning by creating oxygen vacancy that provides sufficient active sites and activates the fast faradaic redox reaction with enhanced energy storge ability of redox-active electrode materials.

Exploring porous carbon (PC)-based materials from low-cost, renewable precursors has always been a challenging objective, since they meet the demands of next-generation supercapacitors and electrochemical devices. Herein, hierarchical multi-heteroatoms co-doped PC (MHPC) materials are successfully achieved by the carbonization and activation of tea waste that used as the self-template. The natural structure of the tea leaves combined with the activation strategy favor the formation of special hierarchical MHPC materials, which are constructed by ultrathin MHPC nanosheets. In addition, the heteroatomic doped carbon derived from organic compounds in tea leaves can act as an ideal precursor to fabricate the resultant heteroatomic functionalized carbon nanosheets. Such heteroatoms content of carbon nanosheets are adjustable by altering pyrolysis condition to effectively enhance the electrochemical performance of PC. After activation by KOH, the as-prepared MHPC, especially MHPC-3 (weight ratio of KOH/pre-carbonized tea waste is 3:1) has a superior supercapacitance of up to 170 and 132 F g−1 at current density of 0.5 and 10 A g−1 in KOH electrolyte, and an excellent capacitance retention of ∼94.8% over 14,000 cycles at 3 A g−1. The result reported here provides valuable guidelines of high-performance energy storge devices from natural sources at the industrial scale.

A facile and general strategy for the large-scale synthesis of ultrasmall metal oxide nanocrystals with particle size of about 2 nm was proposed using coordination polymers (CPs) as templates.

Aim Our previous study demonstrated that chronic intermittent hypobaric hypoxia (CIHH) can confer hepatic protection by reducing endoplasmic reticulum stress (ERS) in high-fat-high-fructose induced metabolic syndrome (MS) rats. It is known that there is a functional coupling between autophagy and ERS. This study aimed to investigate the effect of CIHH on autophagy function and adenosine mono-phosphate-activated protein kinase-mammalian target of rapamycin (AMPKα-mTOR) signaling pathway in hepatic tissue of MS rats. Main methods 6-week old male Sprague-Dawley rats were randomly divided into: control (CON), CIHH (treated with hypobaric hypoxia simulating 5000-m altitude for 28 days, 6 h daily), MS (induced by 16-week high fat diet and 10% fructose water feeding), and MS + CIHH groups (exposed to CIHH after 16-week MS model). Food and water intakes, body weight, Lee's index, fat coefficient, systolic arterial pressure, blood biochemicals, and histopathology of liver were measured, the expression of phosphorylated (p)-AMPK, p-mTOR, autophagy-related and ERS-related proteins were assayed in hepatic tissue. Key findings The MS rats displayed obesity, hypertension, polydipsia, glucose and lipids metabolism disorders, increased inflammatory cytokine, hepatic tissue morphological and functional damage, and the up-regulated expressions of ERS-related, autophagy-related proteins and p-mTOR, and the down-regulated expression of p-AMPKα. All aforementioned abnormalities in MS rats were ameliorated in MS + CIHH rats. Significance In conclusion CIHH confers hepatic protection through activating AMPK-mTOR signaling pathway and the autophagy function, thus inhibiting ERS in hepatic tissue.

An ultrasensitive enzyme-free electrochemical sandwich DNA biosensor is described for the detection of ssDNA oligonucleotides. A DNA sequence derived from the genom of Helicobacter pylori was selected as a model target DNA. The DNA assay was realized through catching target DNA on capture DNA immobilized gold electrode; then labeling the target DNA with reporter DNA (rpDNA) and initiator DNA (iDNA) co-modified gold nanoparticles (AuNPs). The high density of iDNAs serves as one of the amplification strategies. The iDNA triggers hybridization chain reaction (HCR) between two hairpins. This leads to the formation of a long dsDNA concatamer strand and represents one amplification strategy. The electrochemical probe [Ru(NH3)5L]2+, where L stands for 3-(2-phenanthren-9-ylvinyl)pyridine, intercalated into dsDNA chain. Multiple probe molecules intercalate into one dsDNA chain, serving as one amplification strategy. The electrode was subjected to differential pulse voltammetry for signal acquisition, and the oxidation peak current at −0.28 V was recorded. On each AuNP, 240 iDNA and 25 rpDNA molecules were immobilized. Successful execution of HCR at the DNA-modified AuNPs was confirmed by gel electrophoresis and hydrodynamic diameter measurements. Introduction of HCR significantly enhances the DNA detection signal intensity. The assay has two linear ranges of different slopes, one from 0.01 fM to 0.5 fM; and one from 1 fM to 100 fM. The detection limit is as low as 0.68 aM. Single mismatch DNA can be differentiated from the fully complementary DNA. Conceivably, this highly sensitive and selective assay provides a general method for detection of various kinds of DNA.

Alkyne is a useful functionality incorporated in proteins for site-selective bioconjugation reactions. Although effective bioconjugation reactions such as copper(I)-catalyzed and/or copper-free 1,3-dipolar cycloadditions of alkynes and azides are the most common approaches, the development of new alkyne-based bioconjugation reactions is still an ongoing interest in chemical biology. In this work, a new approach has been developed for selective modification of alkyne-linked peptides and proteins through the formation of arylacetylenes by a cross-coupling reaction of 6-membered ring cyclometalated gold(III) (C^N) complexes (HC^N = 2-arylpyridines) with terminal alkynes. Screening of the reaction conditions with a series of cyclometalated gold(III) complexes with phenylacetylene gave an excellent yield (up to 82%) by conducting the reaction in slightly alkaline aqueous conditions. The reaction scope was expanded to various alkynes, including alkyne-linked peptides to achieve up to >99% conversion. Using fluorescent dansyl (1l) and BODIPY (1m)-linked gold(III) complexes, alkyne-linked lysozyme has been selectively modified.

Carcinoembryonic antigen (CEA), a glycoprotein, is a wide-spectrum tumor marker for cancer diagnosis. Developing simple, stable, and low-cost methods for CEA detection is of great importance. In this work, a novel, label-free, and antibody-free electrochemical sandwich CEA biosensor was developed based on concanavalin A (ConA) and a DNA aptamer against CEA. Horse radish peroxidase (HRP) was labeled on the sandwich structure for signal production and amplification. Both the CEA and the HRP bind to ConA through sugar-lectin interactions. Under optimum conditions, the detection linear range was from 5 to 40 ng mL−1 CEA, with a detection limit of 3.4 ng mL−1, lower than the threshold level in human serum for cancer patients (∼10 ng mL−1). The biosensor is reproducible, accurate, specific, and stable, with RSD value of 3% for inter-biosensors, and relative error of

Microalgae are excellent biocatalyst candidates for photo-biocatalytic-asymmetric reduction of prochiral ketones to produce enantiomer alcohols. In the biocatalysis asymmetric reduction of carbonyl group process, the cofactor, NADPH, plays a key role. So the current study focused on the effect of NADPH availability on the reduction. Photosynthesis is a main pathway for NADPH regeneration in microalgae, and the ferredoxin-NADP+ oxidoreductase (FNR) is the key enzyme in this process. In this work, we constructed an engineered cyanobacterium Synechocystis sp. PCC6803::Ω-PpetE-petH to overexpress FNR gene petH to strengthen NADPH regeneration. The results show that the intracellular NADPH content was increased 80.8% compared to the wild type. Applying the Synechocystis sp. PCC6803::Ω-PpetE-petH to catalyze the model asymmetric reduction reaction (reduction of acetophenone to S-phenylethanol), the yield was improved 61.2% compared to the wild-type. This work makes the microalgal biocatalysis asymmetric reduction process become more preponderant via providing a new route to enhance the regeneration of cofactor NADPH. Putative metabolic process of nicotinamide adenine dinucleotide phosphate (NADPH) regeneration and the photo-biocatalytic-asymmetric reduction reaction of prochiral ketones in microalgal cells.

Laser shock-wave-driven nanoparticle implantation (LSWNI) in alloys is a novel surface strengthening technique based on plastic deformation induced by laser shock processing and the excellent properties of hard-phase nanoparticles. In the present work, 50–100 nm silicon carbide (SiC) nanoparticles were successfully implanted into commercially pure aluminum (Al) substrates under the effect of a laser shock wave. After the implantation, stable nanoparticle-reinforced layers were fabricated, and their microstructural response and grain refinement were characterized by X-ray diffraction (XRD), focused ion beam (FIB), and transmission electron microscopy (TEM). In addition, the mechanical properties, including residual stress, nanohardness, elastic modulus, and wear resistance, were investigated. Experimental results showed that Al samples subjected to LSWNI exhibited superior mechanical properties because of the good combination between the gradient microstructure induced by plastic deformation and the gradient distribution of the implanted SiC nanoparticles along the depth direction. Therefore, the overall strengthening effect generated by the LSWNI process can be described as two different modes: (i) the gradient microstructure induced by plastic deformation contributed mainly to the enhancement of residual stress and nanohardness, and (ii) the gradient distribution of the implanted SiC nanoparticles was dedicated primarily to the improvement of the wear resistance. As indicated by the strengthening effect during the LSWNI process, three competing strengthening mechanisms, namely, SiC nanoparticle strengthening, refined grain strengthening, and dislocation strengthening, existed in the gradient-reinforced layers. The detailed contribution of each mechanism to the overall properties of the reinforced layer was determined using the modified Clyne computational model and was described herein. Finally, the wear mechanism of the reinforced layer fabricated by the LSWNI process is revealed.

Herein, we reported a novel strategy to synthesize CuO@SiO2 nanocomposites under neutral conditions with the self-catalysis effect of APTES and CuBA2 as proper precursor. No additional acid or alkali was required as catalyst during the entire process. On the other hand, the catalytic properties of CuO@SiO2 composites were evaluated by catalyzing the reduction of 4-nitrophenol using NaBH4 as the reducing agent. The results revealed that the products exhibit excellent catalytic property and cycling performance.

Noninvasive diagnosis of Helicobacter pylori (H. pylori) infection is very attractive. This study investigated the single strand DNA (ssDNA) acquisition method from H. pylori in dental plaque, and the integration of our previously developed 43-mer H. pylori DNA biosensor with the obtained target ssDNA (tDNA). Dental plaque samples were collected from 34 patients/volunteers, whose gastric H. pylori infection statuses were tested with the 13C urea breath test (UBT). The samples were treated with colony polymerase chain reaction (PCR) to obtain double strand DNA (dsDNA) of 104 basepairs (bp) long. A blocker ssDNA was designed and used in thermal treatment of the dsDNA to release the 104-mer tDNA, which contains the 43-mer DNA sequence in the middle. PCR primers were designed, and the tDNA releasing and detection conditions with the biosensor were optimized. The limit of detection with the biosensor was 12 fM dsDNA. The dental plaque detection results correlated quite well with the UBT results, with a sensitivity of 100%, and specificity of 97%. These results indicate that the residence of H. pylori in dental plaque is highly associated with gastric H. pylori infection, and detection of dental plaque samples with our DNA biosensor is promisingly applicable in noninvasive diagnosis of H. pylori infection.

A highly stable electrochemical acetylcholinesterase (AChE) biosensor for detection of organophosphorus pesticides (OPs) was developed simply by adsorption of AChE on chitosan (CS), TiO2 sol-gel, and reduced graphene oxide (rGO) based multi-layered immobilization matrix (denoted as CS@TiO2-CS/rGO). The biosensor fabrication conditions were optimized, and the fabrication process was probed and confirmed by scanning electron microscopy and electrochemical techniques. The matrix has a mesoporous nanostructure. Incorporation of CS and electrodeposition of a CS layer into/on the TiO2 sol-gel makes the gel become mechanically strong. The catalytic activity of the AChE immobilized CS@TiO2-CS/rGO/glassy carbon electrode to acetylthiocholine is significantly higher than those missing any one of the component in the matrix. The detection linear range of the biosensor to dichlorvos, a model OP compound, is from 0.036μM (7.9 ppb) to 22.6μM, with a limit of detection of 29nM (6.4 ppb) and a total detection time of about 25min. The biosensor is very reproducibly and stable both in detection and in storage, and can accurately detect the dichlorvos levels in cabbage juice samples, providing an efficient platform for immobilization of AChE, and a promisingly applicable OPs biosensor with high reliability, simplicity, and rapidness.

The development of sensitive and convenient strategies for monitoring intracellular caspase-1 activity is of great significance. Herein, a novel fluorescence nanoprobe for caspase-1 activity determination was constructed based on surface energy transfer (SET) between red-emissive carbon dots (RCDs) as a donor, and Au nanorods (AuNRs) as an acceptor. The donor/acceptor pair were covalently bridged with a peptide containing a caspase-1 cleavage site (YVAD) at middle. The stability and dispersivity of the AuNR-Pep-RCD nanoprobe was realized/enhanced by pretreating the AuNRs with PEG-SH. Active caspase-1 cleaves the YVAD site, releasing RCDs and recovering the fluorescence. Synergic effect of the red-emission, sensitive and selective cleavage, and excellent SET efficiency contribute to the nanoprobe with high sensitivity and selectivity, especially in biological samples. More importantly, the nanoprobe can be uptaken by living cells, capable of in-situ intracellular caspase-1 activity imaging. The fluorescence recovery is linearly correlated with caspase-1 activity in the range of 5‒300 ng·mL−1 (2.5 × 10−5‒1.3 × 10−3 U·mL−1), with a limit of detection of 1.76 ng·mL−1 (8.8 × 10-6 U·mL−1). In particular, the fluorescence nanoprobe can accurately detect caspase-1 activity in cells extract, and sensitively probe the caspase-1 activation treatment and inhibition treatment for the intracellular caspase-1 activity levels.

The corrosion resistance and antibacterial activity of dental metal materials are important service performances. In this paper, the TiN and Ti-N-O coatings with different chemical compositions were deposited on Ti6Al4V alloy by physical vapor deposition (PVD). The phase structure, surface morphology and elemental distribution of the Ti-N-O coatings were characterized by XRD, XPS, SEM and EPMA. The electrochemical corrosion behavior of the Ti-N-O coatings in acidic and fluoride-containing artificial saliva was investigated. The antibacterial activity of the coated Ti alloy was evaluated by an in vitro antibacterial test. The results show that with increasing O2 flow rate in the reaction atmosphere, the phase compositions of the Ti-N-O coatings gradually change from TiN to TiNxOy, Ti2O3, TiO2 and Ti3O5. The Ti-N-O coatings show good passivation behavior. Particularly, when the ratio of N2 and O2 flow rate is 2:1, the corrosion current density of the Ti-N-O coated specimen in acid (pH = 5.2) solution is only 6.0 × 10−8 A/cm2. In an acidic solution containing 0.1% NaF, the passivation potential of the Ti-N-O coatings exceeds +1.0 V, and the corrosion resistance is exceeds that of a TiN coating. When the ratio of N2 and O2 flow rate is 1:1, the antibacterial rate of the Ti-N-O coating against Staphylococcus aureus approaches 90%.

A novel and sensitive Helicobacter pylori assay strategy based on linear isothermal amplification reaction (LIAR) and DNAzymes catalyzed DNA sensor was developed. A 17 nt target DNA (tDNA) specific in the H. pylori genome was selected and used as primer in the LIAR. A template DNA was designed to produce an amplicon with Mg2+-dependent and RNA-cleaving DNAzyme (Md-Dz) activity. The amplicon (i.e. Md-Dz) was then detected with the DNA sensor. The DNA sensor was fabricated simply through immobilization of a hairpin DNA that contains both Md-Dz substrate and G-quadruplex DNAzyme (Gq-Dz), on gold electrodes. The Gq-Dz possesses peroxidase activity, catalyzing the electro-redox of the electrochemical signal probe hydroquinon. The LIAR, Md-Dz catalytic reaction, and DNA sensor fabrication and detection processes were characterized and optimized. The LIAR amplification efficiency is as high as ~5 × 105 fold, and the assay strategy is very sensitive, selective and repetitive. The differential pulse voltammetry (DPV) detection signals linearly correlate to the logarithmic tDNA concentration in the range of 0.1–10,000 fM, with a limit of detection (LOD) of 34 aM. The detection linear range for H. pylori genomic DNA is 2.1–67.2 pg, with an LOD of 1.3 pg. Muted DNA sequences and other pathogenic bacteria did not result in interferences. In addition, the DNA sensor is very stable in storage. More importantly, the DNA sensor and the assay strategy could be universally applicable to detect any biological sample and short DNA sequence of interests.

The recognition of mercury(II) ions content in the environment and organisms is of great significance for maintaining the health of the organism and preventing diseases induced by mercury(II) ions. Herein a fluorescent probe which includes rhodamine B and acenaphtho[1,2-b]quinoxaline-9-amin has been designed and synthesized for recognizing mercury(II) ions. The structure of RB-AQ was confirmed by 1H NMR, 13C NMR, HR-MS analyses and single X-ray crystallography. The fluorescent probe RB-AQ exhibited an obvious “turn-on” fluorescence enhancement for mercury(II) ions at 586 nm. RB-AQ showed good recognization capability and selectivity toward mercury(II) ions over other interfering metal ions in solution. Further, the probe has mercury(II) ions imaging capability in cells and zebrafish.

ZnO nanoparticles@SiO2 (ZnO NPs@SiO2) composites have been prepared by a self-catalytic approach in a water–ethanol solution at near neutral conditions. A multifunctional precursor combining not only a silicon alkoxide and a metal carboxylate group, but also a protonated amine group was designed. The intramolecular protonated amine groups could act as catalytic sites for the hydrolysis and condensation of silicon alkoxides. Thus self-catalytic reactions would proceed spontaneously without the addition of any other catalyst. By adjusting the manner of adding the silica source, ZnO NPs with an average diameter of 2.61, 4.00, and 5.72 nm for ZnO NPs@SiO2 composites could be controllably synthesized. Accordingly, the different ZnO NPs@SiO2 composites displayed blue, green, and yellow three emission under ultraviolet light.

Unprecedented stable BINOL/gold(III) complexes, adopting a novel C,O-chelation mode, were synthesized by a modular approach through combination of 1,1'-binaphthalene-2,2'-diols (BINOLs) and cyclometalated gold(III) dichloride complexes [(C^N)AuCl2 ]. X-ray crystallographic analysis revealed that the bidentate BINOL ligands tautomerized and bonded to the AuIII atom through C,O-chelation to form a five-membered ring instead of the conventional O,O'-chelation giving a seven-membered ring. These gold(III) complexes catalyzed acetalization/cycloisomerization and carboalkoxylation of ortho-alkynylbenzaldehydes with trialkyl orthoformates.

An efficient modular approach for the synthesis of propargylamine modified β-cyclodextrins has been developed. Using mono-(6-benzylamino-6-deoxy)-β-cyclodextrins, formaldehyde, and alkynes, mono-(6-(benzylpropargyl)amino-6-deoxy)-β-cyclodextrins have been synthesized through a three-component coupling reaction catalyzed by gold(III) salt in water at 40 °C.

A new approach for selective hydroxylation of non-activated cyclohexanes using dioxirane generated in situ in water through supramolecular control has been developed. Using β-CD and γ-CD as the supramolecular hosts, selective hydroxylation of cyclohexane substrates, including trans/cis-1,4-, 1,3- and 1,2-dimethylcyclohexanes and trans/cis-decahydronaphthalene, was achieved in up to 54% yield in water. Furthermore, site-selective C–H bond hydroxylation of (+)-menthol was achieved by obstructing the approach of dioxirane to the C–H bond with higher steric hindrance through inclusion complexation with β-CD and γ-CD in water.

It is of ongoing interest to develop new approaches for efficient and selective modification of cysteine residues on biomolecules. Here we present a comprehensive study on a newly developed isoxazolinium-mediated cysteine modification of peptides and proteins. Using a stoichiometric amount of isoxazolinium reagents generated in situ from a catalytic amount of silver salts, cysteine-containing peptides can be efficiently modified to afford products in nearly complete conversions. With the optimized conditions, free cysteine containing proteins HSA and BSA, as well as a site-directed mutated therapeutic protein (BCArg) can be efficiently and selectively labelled using small amounts of the isoxazolinium reagents. We find that the phenylacyl thioether linkage bearing an alkyne moiety can be rapidly cleaved under irradiation of UV-A light, giving the formation of a thioaldehyde moiety, which can be converted back to cysteine by reduction. Selective labeling of biomolecules is a powerful technology for chemical biology. Here a silver-catalysed chemoselective modification of cysteine residues by isoxazolinium reagents is described.

Asymmetric catalysis by using novel chiral O,O'-chelated 4,4'-biphenol cyclometalated oxazoline gold(III) complexes has been developed. A high yield (≤89%) and a high enantioselectivity (≤90% ee) were achieved in asymmetric carboalkoxylation of alkynes. Enantioselectivity could be significantly improved from 19% to 90% ee by increasing the steric size of the substituent on the chiral oxazoline ligand. Catalytically active Au

A cerium-based metal-organic tetrahedron has been developed as a highly selective and sensitive fluorescence sensor for the recognition of 4-amino-2,6-dinitrotoluene (4-ADNT). The redox-active tetrahedron could encapsulate 4-ADNT through weak interaction and spatial stereoselectivity, resulting in an enhanced fluorescence. The tetrahedral sensor Ce-ZPS is capable of realizing fluorescent sensing in urine and in cells and thus has the potential to detect 4-ADNT in organisms.

Immunoglobulin M (IgM) is the major antibody in teleost fish and plays an important role in humoral adaptive immunity. The N-linked carbohydrates presenting on IgM have been well documented in higher vertebrates, but little is known regarding site-specific N-glycan characteristics in teleost IgM. In order to characterize these site-specific N-glycans, we conducted the first study of the N-glycans of each glycosylation site of the grass carp serum IgM. Among the four glycosylation sites, the Asn-262, Asn-303, and Asn-426 residues were efficiently glycosylated, while Asn-565 at the C-terminal tailpiece was incompletely occupied. A striking decrease in the level of occupancy at the Asn-565 glycosite was observed in dimeric IgM compared to that in monomeric IgM, and no glycan occupancy of Asn-565 was observed in tetrameric IgM. Glycopeptide analysis with liquid chromatography-electrospray ionization tandem mass spectrometry revealed mainly complex-type glycans with substantial heterogeneity, with neutral; monosialyl-, disialyl- and trisialylated; and fucosyl-and non-fucosyl-oligosaccharides conjugated to grass carp serum IgM. Glycan variation at a single site was greatest at the Asn-262 glycosite. Unlike IgMs in other species, only traces of complex-type and no high-mannose glycans were found at the Asn-565 glycosite. Matrix-assisted laser desorption ionization analysis of released glycans confirmed the overwhelming majority of carbohydrates were of the complex-type. These results indicate that grass carp serum IgM exhibits unique N-glycan features and highly processed oligosaccharides attached to individual glycosites.

Acetylene gas (C2H2) is one of the main arc discharge characteristic gases dissolved in power transformer oil. It is of great potential to monitor the fault gas on-line by applying gas sensor technology. In this paper, gas sensors based on nanorods and nanoneedles assembled hierarchical NiO structures have been prepared. Herein, we focus on investigate the relationship between the sizes of the assembling blocking units and gas sensing properties. It can be found that the addition of CTAB/EG plays a vital role in controlling the sizes of blocking unit and assembly manner of 3D hierarchical structures. A comparison study reveals that an enhanced gas sensing performance toward C2H2 for the sensor based on nanoneedle-assembled NiO flowers occurs over that of nanorod-assembled NiO. This enhancement could be ascribed to the larger specific area of needle-flower, which provides more adsorption and desorption sites for chemical reaction as well as effective diffusion channels for C2H2. Besides, a method of calculating the specific surface area without BET testing was presented to verify the results of gas sensing measurement. The possible growth mechanism and gas sensing mechanism were discussed. Such a synthesis way may open up an avenue to tailor the morphologies and control the sizes of blocking units of some other metal oxides and enhance their gas sensing performances.

Design and fabrication of multifunctional nano-carrier is a promising tool in the field of nanomedicine for glioma theranostics. In this study, blue color nanoparticles with targeted tumor cell staining and drug delivery capabilities were simply fabricated by crosslinking lysine (Lys) and lysine-folic acid (Lys-FA) mixture with genipin as the crosslinking agent through a reversed microemulsion method. Doxorubicin (DOX) as the model drug was loaded through electrostatic interaction. The nanoparticles before (Lys-FA NPs) and after (Lys-FA/DOX NPs) loading of DOX were characterized by ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), dynamic laser light scattering (DLS), transmission electron microscopy (TEM), and fluorescence spectroscopy. Ultimately, the glioma cell staining ability of Lys-FA NPs and cytotoxicity of Lys-FA/DOX NPs were tested in vitro. The results showed that the particle size of Lys-FA NPs can be tuned by adjusting the ratio of Lys to Lys-FA simply. The Lys-FA NPs exhibited dark blue and the blue color is stable under different pH values and temperatures. The feature makes the staining glioma cell pellets visible to naked-eyes. The model drug DOX was loaded on Lys-FA NPs indicated by the increase of size and zeta potential, and change of optical properties. The DOX loaded on the Lys-FA NPs can be sustainedly released, other than burst release. Encouragingly, the Lys-FA NPs can deliver DOX into cells and dramatically reduce cell viability, as proved by U87 cell cytotoxicity analysis and confocal fluorescence imaging. In addition, the Lys-FA NPs (≤2.5 mg mL−1) are nontoxic to CHO cells. In a short, the blue color Lys-FA NPs can visibly stain glioma cell pellets and deliver DOX into glioma cells, which can potentially be applied as a multifunctional nanocarrier for tumor imaging and drug delivery.

A fast and sensitive carcinoembryonic antigen (CEA) aptasensor with multiple detection modes was developed. It is based on hollow gold nanoparticles (HGNPs) and horse radish peroxidase (HRP) as both labels and signal amplification elements. In fabrication, capture DNA (cpDNA) was modified on magnetic beads, and reporter DNA (rpDNA) and HRP were co-modified on HGNPs. A combination DNA, containing a DNA aptamer (GAC-P) segment, hybridized with cpDNA and rpDNA, forming a satellite-structured biosensor. In response to CEA, the aptamer switches its structure, releasing rpDNA/HGNPs/HRP under magnetic separation. The surface plasmon resonance of HGNPs and the HRP enzyme activity of the supernatant were observed/detected with naked eyes, UV–vis spectroscopy, and electrochemistry techniques. The assay time is as short as ~45 min. CEA levels can be differentiated with naked eyes. The absorbance at 677 nm is linearly proportional to CEA concentration from 10 to 250 ng mL−1, with a limit of detection (LOD) of 8.6 ng mL−1. In contrast, the differential pulse voltammetry (DPV) peak current at -0.057 V is linearly correlated with CEA concentration in the range of 2−250 ng mL−1, with an LOD of 0.78 ng mL−1. The LOD values are lower than cancer patient threshold levels. The aptasensor exhibits negligible responses to interfering proteins. In addition, it displays good reproducibility, stability, accuracy and easiness of usage. The recovery rate for CEA spiked human serum samples are 100±5%. The developed assay strategy should provide a general platform for detecting other interested biomarkers.

8-prenylgenistein (8PG) was previously reported to exert stronger osteogenic activity than genistein, a well-known soy phytoestrogen. However, the molecular mechanism underlying the actions of 8PG on osteoblasts was far from clear. In the present study, the osteogenic effects and mechanisms of 8PG and genistein were studied using human BMSC and murine pre-osteoblast MC3T3-E1 cells. Our results indicated that the stimulatory effects of 8PG and genistein on osteoblast differentiation were abolished by co-incubation with MPP (10−6 M, an ERα antagonist), but not PHTPP (10−6 M, an ERβ antagonist). Molecular docking indicated that the binding mode of 8PG toward ERα was similar to that of genistein and therefore could not account for their differential osteogenic actions. In silico target profiling identified the involvement of glycogen synthase kinase-3β (GSK-3β), a key mediator of Wnt/β-catenin pathway, in the actions of 8PG. However, instead of directly inhibiting GSK-3β enzymatic activities, 8PG and genistein were found to induce GSK-3β phosphorylation at Serine-9 in osteoblastic MC3T3-E1 cells. 8PG exerted more potent effects than genistein in stimulating expressions of LRP5, β-catenin, Runx2, osteocalcin, alp, opg, major protein and gene markers involved in Wnt signaling pathway in MC3T3-E1 cells. Moreover, the inhibition of Wnt signaling by DKK1 could be restored by treatment with 8PG and genistein. However, 8PG, but not genistein, stimulated ERα-dependent β-catenin protein expression in MC3T3-E1 cells. Furthermore, the increase in ALP activity, LRP5 and phospho-Akt/Akt expression by 8PG and genistein were abolished by co-treatment with LY294002 (10−5 M, a PI3K pathway inhibitor). Collectively, our results suggested that the osteogenic activities of 8PG was mediated by GSK-3β phosphorylation through the induction of Wnt/β-catenin and ERα-associated PI3K/Akt signaling.

A sensitive, accurate, free of oxygen interference electrochemical sensing approach was developed in this study for H2O2 level, an important parameter in clinical, biological and environmental fields. A boron-doped diamond (BDD) electrode was modified with mesoporous platinum (MPrPt) by electrodeposition of Pt–Cu alloy and anodic dissolution of Cu from the alloy, followed by the electropolymerization of a poly(pyrrole-3-carboxylic acid) (PPy3C) and polypyrrole (PPy) (PPy3C: PPy = 4:1, molar ratio) copolymer. SEM micrographs revealed that MPrPt irregularly spreads on the BDD surface as ~ 100 nm mesoporous and snow-flake-like nanoclusters, with a pore size of 10 ~ 15 nm, and a trace amount of remnant Cu. The resulting Pt roughness factor and the effective surface area of the MPrPt/BDD were significantly larger, and its charge-transfer resistance was much smaller than those of the Pt nanoparticle modified BDD electrode. The PPy3C–PPy/MPrPt/BDD electrode exhibited very much sensitive, selective, precise, accurate, stable, reproducible, and a wide linear range of H2O2 responses at neutral pH under ambient condition, with similar sensitivity and S/N ratio to those under nitrogen protection. The limit of detection (LOD) for H2O2 was 2 μM, with linearity range of 5 μM ~ 49 mM (4 orders of magnitude). The BDD substrate, MPrPt, and the PPy3C–PPy copolymer together exerted a synergic effect to the prominent sensing performance. The detection was free from endogenous oxygen interference, one of the most critical issues in microanalysis, in vivo monitoring and field applications.

A dibromo substituted BOPHY derivative ( 2 ) was prepared and found to exhibit photo-sensitization capability. Rapid oxidation of 80% DPBF at the first 6 min was observed suggesting that 2 is a superior photo-sensitizer than methylene blue. The HOMO–LUMO band gap for the lowest energy absorption bands of the BOPHY 1 is smaller than that of PS 2 , which is in good agreement with the red shift in the absorption observed between 1 and 2 .