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IrO2-Ta2O5/Ti anodes were thermally pretreated by means of baking and continuous heating, and then thermal decomposition at 450 °C for 30 min. To prepare an IrO2-Ta2O5/Ti anode, a Ti substrate was dipped in the precursor, baked at 80 or 90 °C for different periods, and then thermally decomposed at 450 °C for 30 min in the air furnace. The electrochemical properties of prepared IrO2-Ta2O5/Ti anodes were evaluated through their voltammetric charges measured in the 1 M H2SO4 solution and their performance lives tested with 2 Acm−2 in the 1 M H2SO4 + 0.5 M Na2SO4 solution. Microstructures of prepared IrO2-Ta2O5/Ti anodes were characterized with x-ray diffractometer. The chemical compositions and surface morphologies of prepared IrO2-Ta2O5/Ti anodes were analyzed with scanning electron microscope equipped with energy-dispersive x-ray spectrometer. Based on the results of x-ray diffraction, only IrO2-diffracted peaks were detected from prepared IrO2-Ta2O5/Ti anodes. A mud-crack surface structure was seen from prepared IrO2-Ta2O5 coatings. The crack density and the crack width of an IrO2-Ta2O5 coating were obviously affected by different thermal pretreatments of baking methods and heating rates. The crack width of IrO2-Ta2O5 coating increased with an increasing the baking time. A relatively high voltammetric charge can be found from the IrO2-Ta2O5/Ti anode with wide cracks and high crack density. On the other hand, long lifetime values were detected from the IrO2-Ta2O5/Ti anode with a crack width more than 2 μm. The highest voltammetric charge was detected from the IrO2-Ta2O5/Ti anode prepared through baking at 90 °C for 180 s. On the other hand, the longest lifetime was found from the IrO2-Ta2O5/Ti anode pretreated with continuous heating at a rate of 7 °C/min.

The bouncing dynamics of a nanodroplet impacting a superhydrophobic surface under a perpendicular electric field is studied through molecular dynamics (MD) simulations. Using the electric field strength as a parameter, two bouncing regimes are identified: an inertial force rebounding (IFR) regime (E 0.08 V A−1). In the IFR regime, the restitution coefficient, eb, is the same as but the contact time, τc, is shorter than that without an electric field. In the EFFR regime, eb is proportional to the electric field strength, whereas τc decreases with an increase in the electric field strength. On the boundary separating the two regimes (around 0.08 V A−1), both eb and τc increase sharply due to the droplet deformation. The droplet bounces off the surface in the shape of a sphere in the IFR regime and as a long strip in the EFFR regime. A new criterion for the bouncing of nanodroplets subjected to a perpendicular electric field is proposed based on the restitution coefficient, Weber number, characteristic length, and factor Φ. The criterion demonstrates that imposing an electric field can help the bouncing of nanodroplets.

Because electric fields can significantly modify the morphology of impacting droplets, the impact dynamics of droplets subjected to external electric fields have attracted extensive attention in recent years. Owing to the enhanced viscous effect and the altered viscous dissipation mechanisms, nanodroplets show distinctly different impact behaviors from macroscale droplets. However, it is not clear how electric fields affect the impact dynamics of nanodroplets, especially when the field direction is changed. In this study, molecular dynamics (MD) simulations were performed to reveal the bouncing dynamics of a nanodroplet impacting a hydrophobic surface under electric fields with various field strengths and directions. As compared with the case without an electric field, the bouncing dynamics of the nanodroplet were significantly modified in the presence of the electric fields with tilt angles of α = 0°, 30°, 45°, 60°, and 90°, especially when the field strength was higher than 0.08 V A−1. The restitution coefficient, eb, was enhanced by the electric fields at a non-zero α with strengths larger than 0.08 V A−1. Applying an electric field with α = 60° and ≥ 0.08 V A−1 would lead to the maximum bouncing velocity. The contact time was stretched by a perpendicular electric field when E ≥ 0.08 V A−1. When the impact velocity was not sufficient to make a droplet bounce off, an electric field with all directions was capable to cause the opposite.

We have developed highly efficient chemistry to prepare two key intermediates from a Relabactam intermediate available from the process chemistry. The new intermediates enabled us to quickly synthesize other Ralebactam derivatives such as compound 1.

IrO2-Ta2O5/Ti anodes were prepared by coating a Ti substrate with an Ir and Ta containing precursor, followed by oxidization at 450 °C for 30 min. Prior to coating the precursor, three different Ti-pretreatments including grinding with emery paper, etching in a 50 vol.% HCl solution and etching in a 19 g/L NH4HF2 + 5 vol.% HNO3 solution were performed. The cyclic voltammetry (CV) behavior of the prepared IrO2-Ta2O5/Ti anodes were tested in a 1 M H2SO4 solution, and their lifetime values were evaluated in a 1 M H2SO4 + 0.5 M Na2SO4 solution at 30 °C. The experimental results show that the lifetime of an IrO2-Ta2O5/Ti anode is strongly affected by its Ti-pretreatment method. Whereas, the CV behavior of the IrO2-Ta2O5/Ti anodes with different Ti-pretreatments were only slightly changed. A long lifetime and a relatively high voltammetric charge were detected for the IrO2-Ta2O5/Ti anode with the Ti pretreatment of etching in the NH4HF2-based solution for 30 min. Delamination of the IrO2-Ta2O5 layer from the Ti substrate was the main failure mode of an anode during the lifetime test. According to the transmission electron microscopy study, some parts of the IrO2-Ta2O5 layer were detached from the Ti substrate pretreated with mechanical grinding. A high Ir concentration was detected in the IrO2-Ta2O5 adjacent to the Ti substrate pretreated with etching in the 50 vol.% HCl solution. On the other hand, the segregation of Ir and interfacial detachment were not found in the IrO2-Ta2O5 layer near the Ti substrate pretreated with etching in the NH4HF2-based solution. This pretreatment could be suitable for use to achieve a relatively long lifetime and high voltammetric charge on an IrO2-Ta2O5/Ti anode.

In many Internet of Things (IoT) applications, messages may need to be disseminated to some specific objects or nodes using multicast transmissions. In the literature, the multicast routing protocol can be divided into non-geographic-based and geographic-based. Since devices locations can be roughly derived by localization schemes or by GPS devices, geographic-based multicast routing protocols are preferred since they can induce less control packet overheads. However, we observe that existing geographic-based multicast routing schemes have the following two drawbacks. First, network nodes need a lot of computations to decide directions of sending multicast packets. Second, when a network has some holes or voids, the constructed multicast paths will be long, and in some cases, the paths may contain loops. In this work, we proposed a lightweight and distributed geographic multicast routing protocol to solve the above problems. Our scheme contains three phases. First, the first phase selects intermediate nodes to reach multicast destinations. Then, the second phase removes loops and trims routes constructed in the first phase. Finally, the last phase checks if the selected multicast links can further be merged. The simulation results indicate that the proposed scheme can effectively reduce transmission links and shorten path lengths in the constructed multicast paths. To demonstrate the proposed scheme can be applied to IoT applications, we also implement the designed scheme in ZigBee-compliant platforms. The experiment results show that the proposed scheme can also help to reduce multicast latency.

A series of benzimidazole analogs have been synthesized to improve the profile of the previous lead compounds tarocin B and 1. The syntheses, structure–activity relationships, and selected biochemical data of these analogs are described. The optimization efforts allowed the identification of 21, a fluoro-substituted benzimidazole, exhibiting potent TarO inhibitory activity and typical profile for a wall teichoic acid (WTA) biosynthesis inhibitor. Compound 21 displayed a potent synergistic and bactericidal effect in combination with imipenem against diverse methicillin-resistant Staphylococci.

High throughput screening for β-lactamase inhibitors afforded biphenyl hits such as 1. Hit confirmation and X-ray soaking experiments with Pseudomonas Aeruginosa AmpC enzyme led to the identification of an aryl boronic acid-serine complex 4, which was formed from phenyl boronic acid 8 (an impurity in compound 1) and ethylene glycol (the cryoprotectant in the soaking experiment).

A series of pyrrolo-benzo-1,4-diazine analogs have been synthesized and displayed potent Nav1.7 inhibitory activity and moderate selectivity over Nav1.5. The syntheses, structure-activity relationships, and selected pharmacokinetic data of these analogs are described. Compound 41 displayed anti-nociceptive efficacy in the rat CFA pain model at 100 mpk oral dosing.

A series of pyrazoloquinolines, possessing (hetero)arylhydroxymethyl substituents at the quinoline C-4 position were evaluated as PDE10A inhibitors. Among these, methylpyrimidyl analogue 15 was identified as having good rodent and monkey exposure, and a MED of 10 mg/kg in an in vivo model.

A series of pyrazoloquinoline analogs have been synthesized and shown to bind to PDE10 with high affinity. From the SAR study and our lead optimization efforts, compounds 16 and 27 were found to possess potent oral antipsychotic activity in the MK-801 induced hyperactive rat model.

A series of nortropane analogs based on previously reported compound 1 have been synthesized and shown to bind to the nociceptin receptor with high affinity. The synthesis and structure-activity relationships around the C-3 nortropane substitution are described. From the SAR study and hPXR screening effort, compound 15 was identified to possess potent oral antitussive and anxiolytic-like activities in the guinea pig models.

Two new secondary metabolites designated as Sch 419558 ( 1 ) and Sch 419559 ( 2 ), were isolated from the fermentation broth of Pseudomonas fluorescens . Structure elucidation of 1 and 2 was accomplished by spectroscopic data analyses including MS and NMR experiments. Both compounds were identified as lipopeptides containing valine and threonine linked with 1-amino-1-hydroxy-heptadec-9-en-2-one or 1-amino-1-hydroxy-pentadecan-2-one carbon chains, respectively. Characterization of the amino acids was further confirmed by amino acid analysis. Compounds 1 and 2 exhibited antibacterial activity against a sensitized E. coli strain with minimum inhibitory concentration of 0.3 and 0.6 μg/mL, respectively. Overexpression of RpoE in the E. coli strain increased the MIC over 60-fold for compounds 1 and 2 .

A 1:1 mixture of two epimers of an unusual linear diterpene, lingulatusin, was isolated from the whole plant of Aster lingulatus . The structure was determined on the basis of IR, MS and extensive NMR spectral studies, and X-ray crystallographic data.

Two tetracyclic diterpene polyesters, paralinones A and B, with a new carbon framework, were isolated from an acetone extract of the whole plant of Euphorbia paralias. The structures of the compounds were elucidated by high field spectroscopic methods, including 2D NMR techniques and X-ray crystallography.

Two ergostane related steroids, zhankuic acids D and E together with three lanosta related triterpenes, 15α-acetyl-dehydrosulphurenic acid, dehydroeburicoic acid, dehydrosulphurenic acid were isolated from the fruit body of the fungus Antrodia cinnamomea. Their structures were determined by spectral analyses and comparison with known compounds.

DNA ligation catalyzed by all DNA ligases involves two intermediary steps, the formation of the ligase-AMP and the AMP-DNA complexes. A method was developed to purify and analyze the AMP-DNA intermediate from the DNA ligation reaction catalyzed by DNA ligases. This AMP-DNA complex was maximally accumulated by preincubation of human DNA ligase I or II with ATP, followed by interaction with the DNA substrate for 5 s at 0 degrees C. The gel-purified AMP-DNA complex maintained its property as a ligation intermediate. The AMP was directly linked to the 5'-phosphate of DNA with a pyrophosphate bond. The successive ligation reaction following the AMP-DNA complex formation required DNA ligase and Mg2+ ion but was inhibited by ATP and pyridoxal 5'-phosphate, indicating that the availability of the AMP binding site in the enzyme is essential for the completion of the reaction. Furthermore, the formation of the AMP-DNA complex and the subsequent DNA ligation were substrate specific for human DNA ligases I and II. These data, together with previously reported results, suggest that a major difference between human DNA ligases I and II is in their DNA-binding domains. The methods make it convenient to study in depth the kinetics of the overall DNA ligation.

9-beta-D-Arabinofuranosyl-2-fluoroadenine (F-ara-A) is an analogue of adenosine and deoxyadenosine with potent anti-tumor activity. The mechanism of action for this compound has been elucidated as the inhibition of DNA and RNA synthesis, induction of DNA fragmentation, and genetic damage. This study demonstrated that DNA ligase I, an enzyme involved in DNA replication, is a target for the drug action. F-ara-adenine triphosphate (F-ara-ATP) at 80 microM inhibited the activity of DNA ligase I by more than 90%. In contrast, eight other related nucleoside analogues showed no effect on the enzyme activity at 200 microM. F-ara-ATP inhibited DNA ligation in two distinct ways. First, F-ara-ATP directly interacted with DNA ligase I and inhibited the formation of the ligase-AMP complex. This inhibition could not be reversed when free F-ara-ATP was eliminated from the treated enzyme; however, the addition of pyrophosphate, followed by gel filtration chromatography, restored enzyme activity, indicating that F-ara-ATP bound to the enzyme and altered the AMP-binding site. Secondly, the activity of DNA ligase I was inhibited when F-ara-ATP was incorporated into the 3' terminus of the DNA substrate. The dual mode of inhibition of DNA ligase I by F-ara-ATP indicates that its effect on DNA ligation may be important in the inhibition of DNA synthesis and the cytotoxicity of F-ara-A.

DNA ligases play obligatory roles during replication, repair, and recombination. Multiple forms of DNA ligase have been reported in mammalian cells including DNA ligase I, the high molecular mass species which functions during replication, and DNA ligase II, the low molecular mass species which is associated with repair. In addition, alterations in DNA ligase activities have been reported in acute lymphocytic leukemia cells, Bloom's syndrome cells, and cells undergoing differentiation and development. To better distinguish the biochemical and molecular properties of the various DNA ligases from human cells, we have developed a method of purifying multiple species of DNA ligase from HeLa cells by chromatography through DEAE-Bio-Gel, CM-Bio-Gel, hydroxylapatite, Sephacryl S-300, Mono P, and DNA-cellulose. DNA-cellulose chromatography of the partially purified enzymes resolved multiple species of DNA ligase after labeling the enzyme with [alpha-32P]ATP to form the ligase-[32P]AMP adduct. The early eluting enzyme activity (0.25 M NaCl) contained a major 67-kDa-labeled protein, while the late eluting activity (0.48 M NaCl) contained two major labeled proteins of 90 and 78 kDa. Neutralization experiments with antiligase I antibodies indicated that the early and late eluting activity peaks were DNA ligase II and I, respectively. The three major ligase-[32P]AMP polypeptides (90, 78, and 67 kDa) were subsequently purified to near homogeneity by elution from preparative sodium dodecyl sulfate-polyacrylamide gels. All three polypeptides retained DNA ligase activities after gel elution and renaturation. To further reveal the relationship between these enzymes, partial digestion by V8-protease was performed. All three purified polypeptides gave rise to a common 22-kDa-labeled fragment for their AMP-binding domains, indicating that the catalytic sites of ligase I and II are quite similar, if not identical. Similar findings were obtained from the two-dimensional gel electrophoresis of their AMP-binding domains in the trypsin-digested protein fragments. The results also suggested that these isozymes have been derived from the same primordial DNA sequence or from the same precursor protein. The purification scheme and the data obtained will be instrumental for the further elucidation of the biological roles of various DNA ligases from human cells.