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Nanoporous PtFe alloys with two different bimetallic ratios are fabricated by selectively dealloying PtFeAl ternary alloys, characterized by nanoscaled bicontinuous network skeleton with interconnected hollow channels extending in all three dimensions. The reactive components in PtFeAl ternary alloy were sequentially leached out in a highly controllable manner, generating nanoporous architecture with different bimetallic ratios and the typical ligament size as small as 5 nm. These nanoporous PtFe alloys exhibit much enhanced electrocatalytic activity for oxygen reduction reaction compared with the PtFe/C and Pt/C catalysts. The specific and mass activities for oxygen reduction follow the order of nanoporous Pt75Fe25 > nanoporous Pt55Fe45 > PtFe/C > Pt/C. In the absence of any catalyst support, the structure stability of nanoporous PtFe alloys is greatly enhanced with less loss of the electrochemical surface area and the oxygen reduction activity upon long-term potential scan tests compared with PtFe/C and Pt/C catalysts. The as-made nanoporous PtFe alloys thus hold great application potential as promising cathode electrocatalyst in proton exchange membrane fuel cells with the advantages of easy preparation along with superior oxygen reduction activity and durability.

Hierarchical nanoporous platinum-copper (hnp-PtCu) alloy nanoflowers with bimodal pore/ligament size are easily fabricated by selectively dissolving Al atoms and part of Cu atoms from PtCuAl ternary alloy. The dealloyed samples consist of cross-linking porous nanoflowers with interconnected network skeleton and hollow channels penetrated. Hnp-PtCu alloy nanoflowers with different compositions exhibit dramatically enhanced catalytic activities toward the hydrolysis of ammonia borane (AB) compared with their monometallic components. The hnp-Pt35Cu65 alloy shows superior catalytic performance than the other hnp-PtCu catalysts with an initial much higher turnover frequency of 108 mol H2 min-1 (mol Pt)-1. Moreover, the hnp-Pt35Cu65 displays excellent structure stability even after the five runs for the AB hydrolysis. The as-made hnp-PtCu catalysts hold promising application potential toward the AB hydrolysis with the advantages of facile preparation, high yielding, superior catalytic activity, and high structure durability.

Tin sulfide/graphene nanocomposite with hexagonal tin sulfide (SnS2) nanoplates anchored on reduced graphene oxide (RGO) nanosheets was easily synthesized by one-step controllable hydrothermal growth followed by mild reduction. The SnS2 hexagonal-plates distributed tightly and uniformly on the RGO support in a more favorable face-to-face (FTF) manner. The formation of SnS2 nanoplates with hexagonal morphology may result from the accelerating growth of six energetically equivalent high-index (1 1 0) crystal planes and prohibiting growth of the (0 0 1) crystal plane on graphene. The FTF architecture is beneficial for the optimal electric contact efficiency of SnS2 nanoplates with RGO matrix, thus leading to the greatly enhanced electrochemical performance of SnS2/RGO composite than bare SnS2. The graphene-constructed two-dimensional integrated conductive networks minimize the transport paths of electrons and Na ions between electrode and electrolyte as well as accommodate the mechanical strain during long term cyclic. The SnS2/RGO composite exhibits great application potential as an anode for sodium ion batteries with the advantages of unique structure and superior sodium storage performance.

Quasi-period cylindrical nanostructures with both diameters and intervals of about 100 nm are manufactured on the surfaces of Nd

Describing the morphologic features of the thoracic pedicle in patients with adolescent idiopathic scoliosis is necessary for placement of pedicle screws. Previous studies showed inadequate reliability owing to small sample size and heterogeneity of the patients surveyed. To use CT scans (1) to describe the morphologic features of 2718 thoracic pedicles from 60 female patients with Lenke Type 1 adolescent idiopathic scoliosis and 60 age-, sex-, and height-matched controls; and (2) to classify the pedicles in three types based on pedicle width and analyze the distribution of each type. A total of 2718 pedicles from 60 female patients with Lenke Type 1 adolescent idiopathic scoliosis and 60 matched female controls were analyzed via CT. All patients surveyed were diagnosed with adolescent idiopathic scoliosis, Lenke Type 1, at the First Affiliated Hospital of Sun Yat-sen University, and all underwent pedicle screw fixation between January 2008 and December 2013 with preoperative radiographs and CT images on file. We routinely obtained CT scans before these procedures; all patients who underwent surgery during that period had CT scans, and all were available for analysis here. Control subjects had CT scans for other clinical indications and had no abnormal findings of the spine. The control subjects were chosen to match patients in terms of age (15 ± 2.6 years versus 15 ± 2.6 years) and sex. Height of the two groups also was matched (154 ± 9 cm versus 155 ± 10 cm; mean difference, −1.06 cm; 95% CI, −1.24 to −0.81 cm; p < 0.001). Pedicle width and length were measured from T1 to T12. The thoracic spine was classified in four regions: apical vertebra in the structural curve (AV-SC), nonapical vertebra in the structural curve (NAV-SC), apical vertebra in the nonstructural curve (AV-NSC), and nonapical vertebra in the nonstructural curve (NAV-NSC). Pedicles were classified in three types: pedicle width less than 2 mm as Type I, 2 mm to 4 mm as Type II, and greater than 4 mm as Type III. Types I and II were defined as dysplastic pedicles. Paired t test, independent samples t test, one-way ANOVA, followed by Bonferroni’s post hoc test and chi-square or Fisher’s exact tests were used for statistical comparisons between patients and controls, as appropriate. No difference was found between pedicle width on the convex side (PWv) and in controls (PWn), but pedicle width on the concave side (PWc) (4.99 ± 1.87 mm) was found to be narrower than PWv (6 ± 1.66 mm) and PWn (6 ± 1.45 mm). The variation degree of pedicle width (VDPW) was greatest in the AV-SC region (34% ± 37%), in comparison to AV-NSC (20% ± 25%) (mean difference, 14%; 95% CI, 1.15%–27%; p = 0.025), NAV-SC (17% ± 30%) (mean difference, 17%; 95% CI, 7%–27%; p < 0.001), and NAV-NSC (11% ± 24%) (mean difference, 24%; 95% CI, 13%–34%; p < 0.001). Dysplastic pedicles appeared more in patients with adolescent idiopathic scoliosis (22%; 293 of 1322) compared with controls (13%; 178 of 1396) (odds ratio [OR] = 0.51; 95% CI, 0.42–0.63; p < 0.001). In patients with adolescent idiopathic scoliosis, they commonly occurred on the concave side 34% (228 of 661) and on the AV-SC region (32%; 43 of 136). Pedicle width on the concave side was narrower than pedicle width on the convex side and pedicle width in healthy control subjects. The apical vertebra in the structural curve was the most variegated region of the curve with the highest prevalence of dysplastic pedicles. Our study can help surgeons perform preoperative assessments in females with adolescent idiopathic scoliosis, and with preoperative and intraoperative management for difficult pedicle screw placement. In particular, our results suggest that surgeons should exercise increased vigilance when selecting pedicle screw dimensions, especially in the concave aspect of the mid-thoracic curve, to avoid cortical breeches. Future studies should evaluate other Lenke types of adolescent idiopathic scoliosis, and males with adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is a complex genetic disorder characterized by three-dimensional spinal curvatures, affecting 2–3% of school age children, yet the causes underlying AIS are not well understood. Here, we firstly conducted a whole-exome sequencing and linkage analysis on a three-generation Chinese family with autosomal dominant (AD) AIS, then performed targeted sequencing in a discovery cohort comprising 20 AD-AIS families and 86 simplex patients, and finally identified three disease-associated missense variants (c.886G> A, c.1943C> T and c.1760C> T) in the MAPK7 gene (encoding mitogen-activated protein kinase 7). Genotyping of the three rare variants in a Chinese replication cohort comprising 1,038 simplex patients and 1,841 controls showed that their combined allele frequency was significantly over-represented in patients as compared with controls (2.0% (41/2076) vs. 0.7% (27/3,682); odds ratio = 2.7; P = 2.8 × 10−5). In vitro, we demonstrated that the three MAPK7 mutants disrupted nuclear translocation in cellular models, which is necessary for the normal function of MAPK7. In vivo, we also conducted CRISPR/Cas9-mediated deletion of mapk7 in zebrafish recapitulating the characteristic phenotype of idiopathic scoliosis. Taken together, our findings suggest that rare coding variants in MAPK7 predispose to AIS, providing clues to understanding the mechanisms of AIS. This article is protected by copyright. All rights reserved

Mn

Nanoporous PdFe (NP-PdFe) alloy with uniform structure size and controllable bimetallic ratio was easily fabricated by one-step mild dealloying from PdFeAl precursor alloy. NP-PdFe consisted of nanoscaled interconnected network skeleton with bicontinuous hollow channels extending in all three dimensions. Compared with NP-Pd and commercial Pt/C catalysts, the NP-PdFe exhibits superior electrocatalytic activity for oxygen-reduction reaction (ORR) with enhanced specific and mass activities. Electrocatalytic measurements indicated that NP-PdFe possesses higher catalytic durability than Pt/C with the less loss of ORR activity and electrochemical active surface area upon long term potential scan. NP-PdFe alloy also shows higher methanol tolerance relative to Pt/C catalyst. XPS and DFT calculations suggest that the downshift of Pd d-band center after alloying with Fe makes favorable reaction kinetics for ORR with decreased adsorption energy of O and OH on Pd surface.

We describe a simple preparation of amorphous TiO2 nanomaterial through a simple dealloying method with high throughput at room temperature. The as-made TiO2 sample has a unique three-dimensional network structure built by cross-linking nanowires with the diameter of ∼5 nm. As an anode material for Li-ion batteries, the TiO2 product exhibits high capacities and a long cycling life at high rates of 500 and 1000 mA g(-1). In addition, it has a good rate capability. The as-made TiO2 nanowire network shows great application potential as an anode material with the advantages of unique performance and easy preparation.

Bimetallic hierarchical nanostructures have attracted increasing attention for biosensing applications due to their higher electrocatalytic activity and better biocompatibility. In this work, we developed a novel sandwich-type nonenzymatic electrochemical immunosensor for cancer biomarker carbohydrate antigen 15-3 (CA15-3). Hierarchical nanoporous PtFe alloys were used as carriers of the signaling antibody anti-CA15-3 in order to achieve an signal amplification. The immunosensor is constructed by using a graphene as platform and using mesoporous PtFe alloy as labels. The electrochemical signal of the immunosensor was based on the high-electrocatalytic activity of PtFe alloy for the electro-oxidation of H 2 O 2 . Under optimal conditions, this method could detect CA15-3 ranging from 0.002 to 40 U/mL with a low detection limit of 3×10 −4 U/mL. This immunosensor showed good accuracy, stability and fabrication reproducibility. The hierarchical nanoporous metal materials-based immunoassay provides a promising ultrasensitive immunoassay approach for clinical applications.

Nanoporous (NP) PtAu alloy is easily fabricated by a simple and general dealloying method. Characterized by three-dimensional nanospongy architecture with a typical dimension around 5 nm, the as-prepared NP-PtAu alloy shows superior sensing performance towards glucose and hydrogen peroxide (H2O2) with highly sensitive response compared with commercial Pt/C and NP-Pt catalysts. Importantly, NP-PtAu exhibits excellent amperometric durability and long-term stability for H2O2 and glucose. After coating additional nafion on the working electrode, NP-PtAu shows a good anti-interference towards ascorbic acid, uric acid, and dopamine during glucose detection. NP-PtAu alloy holds great application potential for electrochemical sensing with simple preparation, high catalytic activity, and high structure stability.

A counterion-controlled reactivity tuning in Pd-catalyzed highly chemoselective and regioselective dimerization and hydration of terminal alkynes is reported. The use of acetate as counterion favors the formation of an alkenyl alkynyl palladium intermediate which forms hitherto less reported 1,3-diaryl-substituted conjugated enynes after reductive elimination. Using chloride, which is a better leaving group, leads to anion exchange on the alkenylpalladium intermediate with hydroxide which after reductive elimination and tautomerization delivered the hydration products.

We describe the simple preparation of octahedral Mn3O4 nanomaterials with a typical diameter around 300–400 nm using a one step dealloying of MnAl alloy at room temperature. The as-made sample exhibits high performance as an anode material for Li-ion batteries. Electrochemical measurements reveal that the Mn3O4 octahedra have an ultralong cycle life with capacity retentions of 81.3% and 77.8% after 500 cycles at 100 and 300 mA g−1, respectively. Moreover, the Mn3O4 octahedra deliver a stable capacity at a high rate of 1000 mA g−1 with a good rate capability. The as-made Mn3O4 octahedra exhibit great potential for application as anode materials for Li-ion batteries with the advantages of unique performance and easy preparation.

A nanoporous (NP) Fe2O3–CoO nanoparticle composite was easily fabricated by mild dealloying of the ternary alloy Fe5Co5Al90 in NaOH solution. Electrochemical characterization shows that the NP-Fe2O3–CoO composite has a high electrochemical sensing activity towards nitrite, with a fast response less than 3 s, a wide linear range of 0.2–16.2 mM, and a low detection limit of 0.1 μM. In particular, long-term sensing tests demonstrated that the NP-Fe2O3–CoO composite has remarkable sensing durability with almost no activity loss for nitrite detection after 4000 s. The proposed sensor based on the NP-Fe2O3–CoO composite is effective for the determination of nitrite in sausage samples, thus having great potential for electrochemical nitrite sensing.

Currently, available methods for diagnosis of acute pancreatitis (AP) are mainly dependent on serum enzyme analysis and imaging techniques that are too low in sensitivity and specificity to accurately and promptly diagnose AP. The lack of early diagnostic tools highlights the need to search for a highly effective and specific diagnostic method. In this study, we synthesized a conditionally activated, gadolinium-containing, nanoparticle-based MRI nanoprobe as a diagnostic tool for the early identification of AP. Gadolinium diethylenetriaminepentaacetic fatty acid (Gd-DTPA-FA) nanoparticles were synthesized by conjugation of DTPA-FA ligand and gadolinium acetate. Gd-DTPA-FA exhibited low cytotoxicity and excellent biocompatibility when characterized in vitro and in vivo studies. L-arginine induced a gradual increase in the intensity of the T1-weighted MRI signal from 1 h to 36 h in AP rat models. The increase in signal intensity was most significant at 1 h, 6 h and 12 h. These results suggest that the Gd-DTPA-FA as an MRI contrast agent is highly efficient and specific to detect early AP.

In information theory, entropy is a measure of uncertainty. The higher the degree of chaos in a system, the higher its entropy. The concept of entropy has also been applied to the evaluation of transportation systems. Because of the limitation of the existing traffic information collection technology, an entropy-based evaluation method has not been widely applied. With the development of on-board sensors and the Internet of vehicles, vehicle spacing information will be easier to acquire and transmit in real time; furthermore, traffic flow entropy will be calculated in real time. Based on the vehicle spacing on the road, the proportion of the distance between the vehicles was taken as the input data of the entropy calculation, and the summation result was normalised and corrected to obtain the calculation corresponding to the entropy and the degree of disorder. On this basis, the entropy values at different moments were repeatedly calculated, and the dynamic traffic flow entropy on the road segment was summarised. We constructed a one-lane road segment model in the simulation software, recorded the vehicle information, and calculated the dynamic traffic flow entropy. A comparison of the difference in the traffic flow entropy between different proportions of heavy goods vehicles revealed that a large proportion of the heavy goods vehicles corresponded to a large traffic flow entropy, indicating a large degree of disorder. The simulation results showed that the proposed method has good scientific value and is practical.

Fe2O3 nanoparticles are employed as a coating material to optimize the electrochemical performance of LiCoO2 at high voltage. When the current rate is 1 C with the cutoff potential at 4.5 V, the 5 wt.% Fe2O3-coated LiCoO2 delivers an initial capacity of 168.7 mAh g−1. More importantly, its capacity retention after 50 cycles reaches up to 92.6%, whereas the value for pristine LiCoO2 is only 58.5%. The electrochemistry impedance spectroscopy analysis demonstrates that Fe2O3 coating plays an important role in decreasing the charge transfer resistance of cell. Compared with the performance of the Fe2O3-mixed and Fe-doped LiCoO2 samples, it is found that the role of Fe2O3 coating is unique, which may change the characteristic of the surface of LiCoO2 particles. This technique may provide an effective and convenient way for optimizing other electrode materials.

Intramembranous ossification and endochondral ossification are two ways through which bone formation and fracture healing occur. Accumulating amounts of evidence suggests that melatonin affects osteoblast differentiation, but little is known about the effects of melatonin on the process of chondrogenic differentiation. In this study, the effects of melatonin on human mesenchymal stem cells (MSCs) undergoing chondrogenic differentiation were investigated. Cells were induced along chondrogenic differentiation via high-density micromass culture in chondrogenic medium containing vehicle or 50 nm melatonin. Histological study and quantitative analysis of glycosaminoglycan (GAG) showed induced cartilage tissues to be larger and richer in GAG, collagen type II and collagen type X in the melatonin group than in the untreated controls. Real-time RT-PCR analysis demonstrated that melatonin treatment significantly up-regulated the expression of the genes involved in chondrogenic differentiation, including aggrecan (ACAN), collagen type II (COL2A1), collagen type X (COL10A1), SRY (sex-determining region Y)-box 9 (SOX9), runt-related transcription factor 2 (RUNX2) and the potent inducer of chondrogenic differentiation, bone morphogenetic protein 2 (BMP2). And the expression of melatonin membrane receptors (MT) MT1 and MT2 were detected in the chondrogenic-induced-MSCs by immunofluorescence staining. Luzindole, a melatonin receptor antagonist, was found to partially block the ability of melatonin to increase the size and GAG synthesis of the induced cartilage tissues, as well as to completely reverse the effect of melatonin on the gene expression of ACAN, COL2A1, COL10A1, SOX9 and BMP2 after 7 days of differentiation. These findings demonstrate that melatonin enhances chondrogenic differentiation of human MSCs at least partially through melatonin receptors.

A series of hyperbranched waterborne polyurethanes (HWPU-4, HWPU-6 and HWPU-12) containing hydrophobic end groups were prepared by the hyperbranched core and the polyurethane prepolymer. The core was polyol including pentaerythritol (PE-4), hyperbranched polyester with six hydroxyl end groups (HPE-6) and hyperbranched polyester with 12 hydroxyl end groups (HPE-12). The polyurethane prepolymer was synthesized by hexamethylene diisocyanate (HDI), polyethylene glycol (PEG) and hexadecanol. The structures of the hyperbranched cores and HWPUs were characterized by Fourier transform infrared spectra (FTIR), nuclear magnetic resonance spectra (1H NMR and 13C NMR) and gel permeation chromatography (GPC). The influences of HWPU content and structure on its thickening property were studied by the measurement of rotary viscosity. The results showed that the thickening effect of HWPU enhanced with the increase of HWPU content in the aqueous polyurethane emulsion. The thickening effect of HWPU-6 was superior to that of HWPU-4 and HWPU-12 with the same length of hydrophilic chain. In addition, the thickening effect of HWPU with the same core was related to the length of hydrophilic chain and the relative content of hydrophobic end groups.

Nanoporous (NP) PdCu alloys with three different bimetallic ratios are fabricated by selectively dealloying PdCuAl ternary alloys in sulfuric acid solution. Electron microscopy and X-ray diffraction characterizations demonstrate that selective etching of Al from ternary PdCuAl source alloys in acid medium generates three-dimensional bicontinuous ligament-pore nanostructures with a single-phase face-centered-cubic crystalline structure. NP-PdCu alloys show superior electrocatalytic activity and structure stability toward oxygen reduction reaction (ORR) compared with the commercial Pt/C catalyst. The specific and mass activities for ORR follow the order of NP-Pd50Cu50 > NP-Pd75Cu25 > NP-Pd30Cu70 > Pt/C. It is found that among three PdCu samples NP-Pd50Cu50 exhibits the highest methanol tolerance and catalytic durability for ORR. These experimental observations indicate that incorporation of 50 at.% Cu into Pd accompanied with the network nanoarchitecture is beneficial to maximize the ORR performances of Pd.

A nanoporous (NP) PdCo alloy with uniform structure size and controllable bimetallic ratio was fabricated simply by one-step mild dealloying of a PdCoAl precursor alloy. The as-made alloy consists of a nanoscaled bicontinuous network skeleton with interconnected hollow channels that extend in all three dimensions. With a narrow ligament size distribution around 5 nm, the NP PdCo alloy exhibits much higher electrocatalytic activity towards the oxygen-reduction reaction (ORR) with enhanced specific and mass activities relative to NP Pd and commercial Pt/C catalysts. A long-term stability test demonstrated that NP PdCo has comparable catalytic durability with less loss of ORR activity and electrochemical surface area than Pt/C. The NP PdCo alloy also shows dramatically enhanced catalytic activity towards formic acid electrooxidation relative to NP Pd and Pd/C catalysts. The as-made NP PdCo holds great application potential as a promising cathode as well as an anode electrocatalyst in fuel cells with the advantages of superior catalytic performance and easy preparation.

Nanoporous (NP) PtNi alloy is easily fabricated through one step mild dealloying from PtNiAl source alloy. Characterized by three-dimensional nanosponge architecture with the typical dimension size as small as 3 nm, the as-made NP-PtNi alloy exhibits superior sensing performance with superior sensitivity and low detection limit toward ethanol and H2O2 as compared with state-of-the-art Pt/C catalyst due to its unique electrocatalytic activities. In particular, long-term sensing tests demonstrated that NP-PtNi alloy has distinct sensing durability with almost no activity loss upon continuous H2O2 detection for two weeks. Along with these attractive features, the as-made NP-PtNi alloy also behaves a good anti-interference toward glucose, ethanol, ascorbic acid, uric acid, and dopamine during H2O2 detection. NP-PtNi alloy shows great potential for electrochemical sensing applications.

Nanoporous (NP) Fe₂O₃/CoO composites were straightforwardly fabricated by a simple dealloying strategy. Electron microscopy characterization demonstrates that selectively etching FeCoAl ternary alloy in a low concentration of NaOH solution generates a nanoparticle structure with a typical diameter around 80 nm. Interestingly, these nanoparticles consist of open three-dimensional bicontinuous nanosponge structure with uniform pore and ligament distribution around 10 nm. The resulted sample is confirmed to be a mixture of Fe₂O₃ and CoO species based on X-ray photoelectron spectroscopy and X-Ray diffraction analysis. Without any activation pretreatment, NP-Fe₂O₃/CoO composites exhibit excellent electro-oxidation activity toward H₂O₂, such as an excellent sensing performance in a wide linear sensing region from 0.05 to 4.85 mM H₂O₂, fast amperometric response (

Nanoporous PtCo alloy was designed as an antibody carrier for preparation of a highly sensitive immunosensor. The immunosensor was constructed by assembling the capture zeranol antibody on thionine decorated graphene nanosheets modified glassy carbon electrode. With an enzyme-free immunosensor mode, the nanoporous PtCo alloy, synthesized by dealloying method, had shown strong electrocatalytic activity toward antigen–antibody reaction. The use of PtCo alloy carrier offered a high amount of antibody on each immunoconjugate, hence amplified the detectable signal from the electro-reaction of dissolved oxygen. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the recognition of zeranol. Due to the poor conductivity of zeranol, a small amount of zeranol immobilized onto the electrode could result in great change in the electron-transfer resistance. Some factors that would affect the performance of the immunosensor were studied, such as concentration of PtCo, pH, and the ratio of TH to GS. With zeranol concentration range (0.05 to 5.0 ng/mL), the immunosensor exhibited a highly sensitive response to zeranol with a detection limit of 13 pg/mL. The immunosensor was evaluated for bovine urine sample, receiving satisfactory results.

Two bis(ethylenedioxythiophene)naphthalene monomers 1,4-bis(2-(3,4-ethylenedioxythiophene))-naphthalene (M1) and 2,6-bis(2-(3,4-ethylenedioxythiophene))-naphthalene (M2) were synthesized, and corresponding polymer poly(1,4-bis(2-(3,4-ethylenedioxythiophene))-naphthalene) (P1) and poly(2,6-bis(2-(3,4-ethylenedioxythiophene))-naphthalene) (P2) were electrochemically synthesized and characterized. Characterizations of the resulting polymers were performed by cyclic voltammetry, UV–vis spectroscopy and scanning electron microscopy. The oxidation potential of monomer M2 was lower than that of the M1, and the conjugation lengths of both the M2 and P2 were longer than the corresponding M1 and P1, respectively. Spectroelectrochemical analysis revealed that both the polymer films had good electrochromic properties and exhibited multi-electrochromic behaviors. Besides, the corresponding devices P1/Poly(3,4-ethylenedioxythiophene) (PEDOT) device and P2/PEDOT device showed satisfactory optical contrast (ΔT%), fast response time and excellent cyclic voltammetry stability. The electrochromic properties of two EDOT-naphthalene-EDOT style polymers are dependent on the position of substitution.

A well-defined amphiphilic graft copolymer, poly(6-methyl-1,2-heptadien-4-ol)-g-poly(2-(dimethylamino)ethyl methacrylate) (PMHDO-g-PDMAEMA), has been synthesized by the combination of living coordination polymerization, single electron transfer-living rad

A series of polyallene-based well-defined amphiphilic graft copolymers, poly(6-methyl-1,2-heptadiene-4-ol)-g-poly(2-(diethylamino)ethyl methacrylate) (PMHDO-g-PDEAEMA), was synthesized through the grafting-from technique. First, double-bond-containing PMH

A donor–acceptor type monomer 4,7-dicarbazol-9-yl-2,1,3-benzothiadiazole (CBTD) was synthesized by modified Ullmann coupling reaction and its corresponding polymer (PCBTD) was obtained via electrochemical polymerization. Characterizations of the resulting polymer PCBTD were performed by cyclic voltammetry, UV–vis spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The polymer displayed multiple colors changed from yellow to yellowish green, green, and turquoise blue with the applied potential. The UV–vis spectra depicted that polymer film have two absorption bands as expected for this type of donor–acceptor polymer, at 320 and 467 nm, which attributed to the π–π* transition and intrachain charge transfer transition, respectively. Further, electrochemical and optical band gaps were obtained by using their oxidation and reduction onset potentials and absorption edges, respectively. The optical contrasts of the PCBTD film were found to be 28.1% at 420 nm and 49.9% at 800 nm in the visible region. The dual type electrochromic device constructed utilizing PCBTD and poly(3,4-ethylenedioxythiophene) showed a maximum contrast (ΔT %) of 49.4% at 620 nm with response time of 0.6 s and exhibited high coloration efficiency (1728 cm2 C− 1) and good stability. These properties make the polymer a suitable material for electrochromic applications.

Nanoporous (NP) PdCu alloy is easily fabricated by dealloying PdCuAl ternary alloy in dilute sulfuric acid. Selectively dissolving Al from PdCuAl alloy generates the three-dimensional uniform nanosponge architecture with narrow ligament size distribution. Benefitting from the unique nanoporous architecture and the alloying effect, the as-made NP-PdCu exhibits outstanding sensing performance towards the detection of hydrogen peroxide (H

Tumor necrosis factor-alpha (TNFα) plays a pivotal role in inflammation-related osteoporosis through the promotion of bone resorption and suppression of bone formation. Numerous drugs have been produced to treat osteoporosis by inhibiting bone resorption, but they offer few benefits to bone formation, which is what is needed by patients with severe bone loss. Melatonin, which can exert both anti-inflammatory and pro-osteogenic effects, shows promise in overcoming TNFα-inhibited osteogenesis and deserves further research. This study demonstrated that melatonin rescued TNFα-inhibited osteogenesis of human mesenchymal stem cells and that the interactions between SMURF1 and SMAD1 mediated the crosstalk between melatonin signaling and TNFα signaling. Additionally, melatonin treatment was found to downregulate TNFα-induced SMURF1 expression and then decrease SMURF1-mediated ubiquitination and degradation of SMAD1 protein, leading to steady bone morphogenetic protein-SMAD1 signaling activity and restoration of TNFα-impaired osteogenesis. Thus, melatonin has prospects for treating osteoporosis caused by inflammatory factors due to its multifaceted functions on regulation of bone formation, bone resorption, and inflammation. Further studies will focus on unveiling the specific mechanisms by which melatonin downregulates SMURF1 expression and confirming the clinical therapeutic value of melatonin in the prevention and therapy of bone loss associated with inflammation.

A simple and convenient dealloying method is used to prepare nanoporous (NP) PdCr alloys with uniform ligament dimensions and controllable bimetallic ratio. The structural characterization methods demonstrate that the NP-PdCr alloy is comprised of a nanoscaled interconnected network skeleton and hollow channels extending in all three dimensions. Electrocatalytic measurements indicated that the as-made NP-Pd75Cr25 alloy exhibits superior specific and mass activities as well as higher catalytic stability toward oxygen reduction reaction compared with NP-Pd67Cr33, NP-Pd, and commercial Pt/C catalysts. X-ray photoelectron spectroscopy and density functional theory calculations both demonstrate that the weakened Pd-O bond and improved ORR performances depend on the downshifted d-band center of Pd due to the alloying of Pd with Cr (25 at%). It is expected that the as-made NP-PdCr alloy has prospective application as a cathode electrocatalyst in fuel-cell-related technologies with the advantages of superior overall ORR performances, unique structural stability, and easy preparation.

In current work highly sensitive and stable electrochemical sensor for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) is constructed based on the hierarchical nanoporous (HNP) PtTi alloy. The HNP-PtTi alloy is simply fabricated by two-step dealloying process, characterized by the bimodal ligament/pore size distributions and interconnected hollow channels. The HNP structure with the advantages of large surface area, excellent structure stability, and rich pore channels is used for facilitating the electron conductivity and the mass transfer. Combined with the dual effects of the bimodal nanoporous architecture and the excellent electrocatalytic activity of PtTi alloy, the constructed sensor exhibits high electrochemical sensing activity with wide linear responses from 0.2 to 1mM, 0.004 to 0.5mM, and 0.1 to 1mM for simultaneous detection of AA, DA, and UA, respectively. In addition, HNP-PtTi alloy also shows long-term sensing stability towards the AA, DA, and UA detection and behaves as a good anti-interference towards NaCl, KCl, FeCl3, CuCl2, AlCl3, glucose, and H2O2. The HNP-PtTi alloy manifests intriguing application potential as the candidate for the application of the electrochemical sensor for simultaneous detection of AA, DA, and UA.

Heparan sulfate (HS) interacts with growth factors and has been implicated in regulating chondrogenesis. However, the effect of HS on TGF-β-mediated mesenchymal stem cell (MSC) chondrogenesis and molecular mechanisms remains unknown. In this study, we explored the effects of exogenous HS alone and in combination with TGF-β3 on chondrogenic differentiation of human MSCs and possible signal mechanisms. The results indicated that HS alone had no obvious effects on chondrogenic differentiation of human MSCs and TGF-β/Smad2/3 signal pathways. However, the combined TGF-β3/HS treatment resulted in a significant increase in GAG synthesis, cartilage matrix protein secretion, and cartilage-specific gene expression compared to cells treated with TGF-β3 alone. Furthermore, HS inhibited type III TGF-βreceptors (TβRIII) expression and increased TGF-β3-mediated ratio of the type II (TβRII) to the type I (TβRI) TGF-βreceptors and phosphorylation levels of Smad2/3. The inhibitor of the TGF-β/Smad signal, SB431542, not only completely inhibited HS-stimulated TGF-β3-mediated Smad2/3 phosphorylation but also completely inhibited the effects of HS on TGF-β3-induced chondrogenic differentiation. These results demonstrate exogenous HS enhances TGF-β3-induced chondrogenic differentiation of human MSCs by activating TGF-β/Smad2/3 signaling.

A nanoporous PdTi (NP-PdTi) alloy with uniform ligament size and controllable bimetallic ratio was easily fabricated by a one-step mild dealloying process of PdTiAl (precursor alloy). NP-PdTi consisted of an interconnected network of nanoscale ligaments with bicontinuous hollow channels extending in all three dimensions. Electrocatalytic measurements indicated that NP-PdTi had superior electrocatalytic activity in the oxygen reduction reaction (ORR) with enhanced specific and mass activities as well higher methanol tolerance relative to Pt/C. Interestingly, NP-PdTi showed higher catalytic durability than Pt/C with a lower decrease in the ORR activity and electrochemical surface area of the metal upon 5000 potential cycles in an acidic solution. DFT calculations demonstrated that alloying Pd with Ti could bring favorable electronic perturbation with the downshifted d-band center of Pd, leading to a weakened PdO bond and improved ORR performance. The excellent electrocatalytic performance in ORR renders NP-PdTi alloys attractive as efficient cathode electrocatalysts in fuel-cell-related technologies.

We measured developmental time and survival rate of the immature stages as well as longevity and fecundity of the adult stage of sweetpotato whitefly, the B biotype of Bemisia tabaci, on seven marginal host plant species (defined as species on which the B biotype occurred occasionally in the field). Although causing little damage in the field, B. tabaci can exploit all of the marginal plant species as hosts. Solanum tuberosum, Lablab purpureus and Helianthus annuus can be regarded as preferred hosts compared to the other four. Our results revealed that most mortality occurs in the younger nymph stages of B. tabaci on the host plant species. Oviposition preference was not correlated with feeding preference. The shortest developmental time of B. tabaci was found on L. purpureus and H. annuus, and the highest survivorship and fecundity were observed on S. tuberosum and L. purpureus, respectively. The discrepancies are indicative of different strategies by B. tabaci in adjusting to novel host plants. Our find...

A star-shaped monomer tris[4-(3,4-ethylenedioxythiophene)phenyl]amine (TEPA) was successfully synthesized and electrochemically polymerized to obtain a multielectrochromic polymer (PTEPA). The electroactive yellowish green color film converted to green, blue and steel blue in turn upon applied stepwise oxidations from −0.4 to 0.95 V. The UV–vis spectra showed that the dedoped polymer film has two absorption bands located at 448 and 686 nm, respectively, and the optical band gap was calculated to be 1.3 eV. Maximum contrast (Δ T %) and response time of the PTEPA film were measured as 26.84% and 0.94 s at 448 nm, 17.03% and 1.11 s at 686 nm, respectively. An electrochromic device (ECD) based on PTEPA and poly(3,4-ethylenedioxythiophene) (PEDOT) was also constructed and characterized. This ECD was found to have a neutral green state, good switching times, reasonable contrast, satisfactory optical memories and redox stability.

1,3-Bis(9H-carbazol-9-yl)benzene monomer (BCB) is successfully synthesized. Poly(1,3-bis(9H-carbazol-9-yl)benzene) (PBCB) is electrochemically synthesized and characterized. The PBCB shows high outstanding optical contrast (60.98%) and reasonable transparency, with color changes from desirable transparent colorless to yellowish green, and then to green color upon the application of potentials ranging from 0 to 1.25 V. The color switching time and bleaching time of the PBCB film are 2.07 s and 0.45 s at 427 nm. Electrochromic device (ECD) based on PBCB and poly(3,4-ethylenedioxythiophene) (PEDOT) is also constructed and characterized. PBCB/PEDOT device shows a maximum contrast (Δ T %) of 26.64% at 427 nm with response time of 0.90 s and of 43.67% at 625 nm with response time of 0.66 s, respectively. Particularly, the device exhibits transmissive blue at neutral state, good optical memory ability and remarkable stability after 1000 cycles. These properties make the polymer a suitable material for electrochromic applications.

Nanoporous (NP) PtCo and PtNi alloy ribbons with predetermined bimetallic compositions are easily fabricated by one step of mild dealloying, which are characterized by uniform three-dimensional bicontinuous network architecture with the ligament size as small as 3 nm. Compared with E-TEK Pt/C catalyst, the as-made NP-PtCo(Ni) alloys exhibit superior specific activity with the lower peak potential and enhanced CO-tolerance toward methanol electrooxidation. More importantly, these nanomaterials also show much higher structure stability with little loss of the electrochemical surface area of Pt upon 5000 potential cycles in acid solution. X-ray photoelectron spectroscopy and DFT calculations revealed that alloying with Co or Ni modifies the electronic structure of Pt with the downshift of Pt d-band center, thus resulting in the improved methanol oxidation activity and decreased CO poisoning.

This study presented the synthesis and characterization of glucosamine (GlcN) modified poly (ethylene glycol) (PEG) hydrogels. The chemical structure was characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. The morphology of hydrogels was observed by scanning electron microscopy (SEM). The results indicated that GlcN was successfully incorporated into PEG hydrogel network. Moreover, the data of the swelling ratio showed that the ratio of GlcN-modified PEG hydrogels was lower than that of pure poly(ethylene glycol) diacrylated (PEGDA). Biocompatibility of unreacted GlcN monomer and GlcN-modified hydrogels was also evaluated in vitro. Compared with glucosamine hydrochloride, 2 and 5 mM N-acroloyl-glucosamine monomer exhibited no toxicity against bone marrow stromal cells (BMSCs), while with the concentration increased to 10 mM, cell viability appeared to decrease. However, when BMSCs were encapsulated in GlcN-modified hydrogels via photopolymerization method, cells remained vigorous viability. Metabolic activity of the encapsulated cells demonstrated GlcN-modified hydrogels was favorable for cell proliferation. Compared with free GlcN, covalent binding GlcN showed lower cytotoxicity and higher cell proliferation properties. As a result, GlcN-modified PEGDA hydrogels could be used as safe and injectable cell carriers for in situ tissue engineering applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Interests in using nanoporous metals for biosensing applications have been increasing. Herein, nanotubular mesoporous PdCu (NM-PdCu) alloy is used to fabricate a novel label-free electrochemical immunosensor for cancer biomarker carcinoembryonic antigen (CEA). It operates through physisorption of anti-CEA on NM-PdCu and the mixture of sulfonated graphene sheets (HSO(3)-GS) and thionine (TH) functionalized glassy carbon electrode interface as the detection platform. In this study, chitosan (CS)-PdCu is bound very strongly to carcinoembryonic antibody (anti-CEA), because of the good electron conductivity, high surface area, and good biocompatibility. CS-PdCu is immobilized on electrodes by electrostatic interactions between the negatively charged sulfo group of HSO(3)-GS and the abundant positively charged amino groups of chitosan. TH acts as the redox probe. Under the optimized conditions, the electrochemical immunosensor exhibits a wide working range from 0.01 to 12 ng/mL with a low detection limit of 4.86 pg/mL. The accuracy, reproducibility, and stability of the immunosensor are acceptable. The assay is evaluated for real serum samples, receiving satisfactory results. The nanoporous metal materials-based immunoassay provides a promising approach in clinical application and thus represents a versatile detection method.

In this work, nanoporous PdCu alloys (np-PdCu) with predetermined bimetallic ratios are fabricated by selectively dealloying PdCuAl ternary alloys in 1.0 M NaOH solution. Electron microscope and X-ray diffraction characterizations show that the nanoporous metals have three-dimensional bicontinuous ligament-pore structure with uniform ligament size. Electrochemical measurements demonstrate that np-PdCu has greatly enhanced electrocatalytic activity and structure stability towards formic acid oxidation (FAO) compared with nanoporous Pd (np-Pd). The surface specific activities of the nanoporous metals follow the order that np-Pd(50)Cu(50) > nP-Pd(75)Cu(25) > np-Pd(30)Cu(70) > np-Pd. The peak current density on np-Pd(50)Cu(50) shows the highest value, which is about six times of that on np-Pd. The alloy ratio also has a significant effect on the electrocatalytic behavior of the PdCu alloy towards FAO. When the Cu content is lower than 50 at.%, the FAO is mainly through the direct pathway; when the Cu content reaches 70 at.%, the FAO through the CO pathway increases. Moreover, electrochemical stripping experiment and continuous potential scan demonstrate that np-Pd(50)Cu(50) has a better resistance to CO poisoning and enhanced structure stability compared with other alloy samples. These results indicate the potential application of the np-Pd(50)Cu(50) in direct formic acid fuel cell. (C) 2011 Elsevier B.V. All rights reserved.

It is of critical importance to design and fabricate highly active and durable oxygen reduction reaction (ORR) catalysts for the application of proton exchange membrane fuel cells (PEMFCs). By a simple two-step dealloying process, the active components in a Pt/Ni/Al ternary alloy were sequentially leached out in a highly controllable manner, generating a novel nanoporous surface alloy structure. Characterized by an open bicontinuous spongy morphology, the resulting nanostructure is interconnected by ∼3 nm diameter ligaments which are comprised of a Pt/Ni alloy core and a nearly pure Pt surface. In the absence of any catalyst support, these nanoporous surface alloys show much enhanced durability and electrocatalytic activity for ORR as compared to the commercial Pt/C catalyst. At a high potential, such as 0.9 V versusRHE, nanoporous Pt/Ni surface alloys show a remarkable specific activity of 1.23 mA cm−2. These nanomaterials thus hold great potential as cathode catalysts in PEMFCs in terms of facile preparation, clean catalyst surface, and enhanced ORR activity and durability.

Interspecific interactions between Bemisia tabaci (Gennadius) and the spidermite Tetranychus truncatus Ehara were evaluated by observation of behavioral responses over 30 min intervals on cowpea leaves. The response of adult female whiteflies was observed on 4 classes of leaf: (1) uninfested (2) previously fed upon by spidermite nymphs, (3) spidermite nymphs and webbing present, and (4) spidermite adults present. Likewise, adult female spidermite response was observed on (1) leaves uninfested with whiteflies, (2) leaves previously fed upon by whitefly nymphs, (3) leaves with whitefly nymphs present, and (4) leaves with whitefly adults present. Spidermites generally had a greater effect on whitefly behavior than vice versa. Whitefly feeding duration decreased while labial tapping duration and frequency increased on all 3 types of mite-infested leaves compared to uninfested leaves. Although whitefly oviposition duration and frequency did not change on leaves infested with spidermite nymphs, whitefly fecundity decreased compared to untreated leaves. Although whitefly effects on spidermite behavior were less marked, nevertheless, duration and frequency of cheliceral tapping by spidermites did increase in the presence of whiteflies, although duration or frequency of feeding did not. Thus, one would predict that spidermites would win out in competition with whiteflies on a common host plant. Behavioral observations of interactions between herbivores can provide valuable insight into competitive relationships which should, however, be verified by field studies. Interacciones interespecificas entre hembras adultas de la mosca blanca Bemisia tabaci y el y el acaro Tetranychus truncatus fueron evaluados mediante observaciones durante intervalos de 30 minutos en las hojas de caupi. Las respuestas de la mosca blanca se observo en 4 clases de hoja: (1) no infestadas (2) anteriormente alimentado por ninfas del acaro, (3) con ninfas y telarana del acaro presentes, y (4) con adultos del acaro presentes. Del mismo modo, la respuesta de las crias de arana se observo que (1) hojas no infestadas, (2) hojas previamente alimentado por ninfas de mosca blanca, (3) hojas con ninfas de mosca presentes, y (4) hojas con los adultos de mosca presentes. Los acaros en general tuvieron un mayor efecto sobre el comportamiento de la mosca blanca que a la inversa. Duracion en alimentacion de la mosca blanca se disminuyo, mientras que la duracion y frecuencia de pulsaciones labiales aumentaron en presencia de los tres tipos de hojas infestadas por acaros en comparacion con hojas no infestadas. A pesar de la duracion y la frecuencia de ovoposicion de mosca blanca no ha cambiado en las hojas infestadas con ninfas de las crias de arana, la fecundidad de la mosca blanca se disminuyo en comparacion con las hojas no tratadas. Aunque los efectos sobre el comportamiento de las crias de arana mosca blanca fueron menores, sin embargo, la duracion y frecuencia de pulsaciones chelicerales por los acaros se incremento en presencia de la mosca blanca, aunque no hubo cambio en la duracion o frecuencia de la alimentacion. Por lo tanto, se podria predecir que se ganaria los acaros en una competencia con la mosca blanca cuando compartiendo una planta huesped. Aunque observaciones del comportamiento pueden proporcionar informacion valiosa sobre relaciones de competencia entre herbiveros, sin embargo, seria siempre necesario verificarlas por estudios de campo. View this article in BioOne

Nanoporous platinum was fabricated by a simple dealloying method. Electron microscope characterizations show that selectively etching Al from PtAl alloy precursors in alkali or acid solution can both easily prepare three-dimensional bicontinuous network nanostructures of Pt. The resulted nanostructure exhibited much enhanced catalytic performance towards methanol electrooxidation compared with commercial Pt/C catalyst. More importantly, CO stripping and potentiostatic tests demonstrated that nanoporous Pt has much higher long-term catalytic stability and CO resistance than the Pt/C catalyst. Copyright © 2011 VBRI press.

We describe a general strategy to fabricate a new type of nanoporous core/shell structured bimetallic nanocomposites with controllable metal components. Nanoporous copper (NPC) obtained by dealloying Cu/Al alloy is used as both reducing agent and three-dimensional substrate. Electron microscope and X-ray diffraction characterizations demonstrated that a simply galvanic-replacement reaction with H(2)PtCl(6) aqueous solution can easily generate nanoporous core/shell structure with a thin Pt/Cu alloy shell and Cu (or Pt/Cu alloy) core. The morphology and crystal structure evolution of the nanocomposites are studied and discussed in detail. The as-prepared bimetallic PtCu nanocomposites show greatly enhanced catalytic activity and stability toward methanol electro-oxidation as compared with commercial Pt/C catalyst. This facile in situ preparation strategy is also suitable for large-scale production of this novel and inexpensive catalyst.

A novel nonenzymatic immunosensor for sensitive detection of Microcystin-LR (MC-LR) is constructed using a graphene platform combined with mesoporous PtRu alloy as a label for signal amplification. Primary antibody-Microcystin-LR (Ab1) is immobilized onto the surface of a graphene sheet (GS) through an amidation reaction between the carboxylic acid groups attached to the GS and the available amine groups of Ab1. Mesoporous PtRu alloy, prepared by corrosion PtRuAl alloys, is employed as a label to immobilize secondary antibody (Ab2). The resulting nanoparticles, PtRu-Ab2, are used as labels for the immunosensor to detect MC-LR. Under optimal conditions, the immunosensor exhibits a wide linear response to MC-LR that ranges from 0.01 to 28 ng·mL−1, with a low detection limit of 9.63 pg·mL−1 MC-LR. The proposed immunsensor shows good reproducibility, selectivity, and stability. The assayed results of polluted water with the sandwich-type sensor are acceptable. Importantly, this methodology may provide a promising ultrasensitive assay strategy for other environmental pollutants.

Nanoporous silver (NPS) and copper (NPC) obtained by dealloying AgAl and CuAl alloys, respectively, were used as both three-dimensional templates and reducing agents for the fabrication of nanoporous PtAg (NPS-Pt) and PtCu (NPC-Pt) alloys with hollow ligaments by a simple galvanic replacement reaction with H(2)PtCl(6). Electron microscopy and X-ray diffraction characterizations demonstrate that NPS and NPC with similar ligament sizes (30-50 nm) have different effects on the formed hollow nanostructures. For NPS-Pt, the shell of the hollow ligament is seamless. However, the shell of NPC-Pt is comprised of small pores and alloy nanoparticles with a size of similar to 3 nm. The as-prepared NPS-Pt and NPC-Pt exhibit remarkably improved electrocatalytic activities towards the oxidation of ethanol and H(2)O(2) compared with state-of-the-art Pt/C catalyst, and can be used for sensitive electrochemical sensing applications. The hierarchical nanoporous structure also provides a good microenvironment for enzymes. After immobilization of glucose oxidase (GOx), the enzyme modified nanoporous electrode can sensitively detect glucose in a wide linear range (0.6-20 mM). (C) 2011 Elsevier B.V. All rights reserved.

Electrochemical copolymerization of 1,4-bis(2-thienyl)-naphthalene (BTN) and 2,2′-bithiophene (BT) is carried out in acetonitrile (ACN) containing sodium perchlorate (NaClO4) as a supporting electrolyte. Cyclic voltammetry (CV), UV–vis and FT-IR analyzes confirm that the resulting polymer is a copolymer rather than a blend or a composite of the respective homopolymers. The obtained P(BTN-co-BT) film exhibits five different colors (orange yellow, yellowish green, green, greenish blue and blue) under various potentials, revealing distinct electrochromic properties from that of the BTN homopolymer film. Maximum contrast (ΔT%) and response time of the copolymer film are measured as 32.7% and 0.59 s at 750 nm. Electrochromic device (ECD) based on P(BTN-co-BT) and poly(3,4-ethylenedioxythiophene) (PEDOT) is also constructed and characterized. This ECD shows a maximum optical contrast (ΔT%) of 24.2% in visible region with a response time of 0.32 s at 780 nm. The coloration efficiency (CE) of the device is calculated to be 308 cm2 C−1 at 780 nm.