Redox poly[Ni(saldMp)] modified activated carbon electrode in electrochemical supercapacitors

The complex (2,2-dimethyl-1,3-propanediaminebis(salicylideneaminato))-nickel(II), [Ni(saldMp)], was oxidatively electropolymerized on activated carbon (AC) electrode in acetonitrile solution. The poly[Ni(saldMp)] presented an incomplete coated film on the surface of carbon particles of AC electrode by field emission scanning electron microscopy. The electrochemical behaviors of poly[Ni(saldMp)] modified activated carbon (PAC) electrode were evaluated in different potential ranges by cyclic voltammetry. Counterions and solvent swelling mainly occurred up to 0.6 V for PAC electrode by the comparison of D^1/2C values calculated from chronoamperometry experiments. Both the Ohmic resistance and Faraday resistance of PAC electrode gradually approached to those of AC electrode when its potential was ranging from 1.2 V to 0.0 V. Galvanostatic charge/discharge experiments indicated that both the specific capacitance and energy density were effectively improved by the reversible redox reaction of poly[Ni(saldMp)] film under the high current density up to 10 mA cm⁻² for AC electrode. The specific capacitance of PAC electrode decreased during the first 50 cycles but thereafter it remained constant for the next 200 cycles. This study showed the redox polymer may be an attractive material in supercapacitors.     

A Nitric Oxide-Responsive Quorum Sensing Circuit in Vibrio harveyi Regulates Flagella Production and Biofilm Formation

Cell signaling plays an important role in the survival of bacterial colonies. They use small molecules to coordinate gene expression in a cell density dependent manner. This process, known as quorum sensing, helps bacteria regulate diverse functions such as bioluminescence, biofilm formation and virulence. In Vibrio harveyi, a bioluminescent marine bacterium, four parallel quorum-sensing systems have been identified to regulate light production. We have previously reported that nitric oxide (NO), through the H-NOX/HqsK quorum sensing pathway contributes to light production in V. harveyi through the LuxU/LuxO/LuxR quorum sensing pathway. In this study, we show that nitric oxide (NO) also regulates flagellar production and enhances biofilm formation. Our data suggest that V. harveyi is capable of switching between lifestyles to be able to adapt to changes in the environment.     

Sphingosine Kinase Interacting Protein is an A‐Kinase Anchoring Protein Specific for Type I cAMP‐Dependent Protein Kinase

The compartmentalization of kinases and phosphatases plays an important role in the specificity of second‐messenger‐mediated signaling events. Localization of the cAMP‐dependent protein kinase is mediated by interaction of its regulatory subunit (PKA‐R) with the versatile family of A‐kinase‐anchoring proteins (AKAPs). Most AKAPs bind avidly to PKA‐RII, while some have dual specificity for both PKA‐RI and PKA‐RII; however, no mammalian PKA‐RI‐specific AKAPs have thus far been assigned. This has mainly been attributed to the observation that PKA‐RI is more cytosolic than the more heavily compartmentalized PKA‐RII. Chemical proteomics screens of the cAMP interactome in mammalian heart tissue recently identified sphingosine kinase type 1‐interacting protein (SKIP, SPHKAP) as a putative novel AKAP. Biochemical characterization now shows that SPHKAP can be considered as the first mammalian AKAP that preferentially binds to PKA‐RIα. Recombinant human SPHKAP functions as an RI‐specific AKAP that utilizes the characteristic AKAP amphipathic helix for interaction. Further chemical proteomic screening utilizing differential binding characteristics of specific cAMP resins confirms SPHKAPs endogenous specificity for PKA‐RI directly in mammalian heart and spleen tissue. Immunolocalization studies revealed that recombinant SPHKAP is expressed in the cytoplasm, where PKA‐RIα also mainly resides. Alignment of SPHKAPs' amphipathic helix with peptide models of PKA‐RI‐ or PKA‐RII‐specific anchoring domains shows that it has largely only PKA‐RIα characteristics. Being the first mammalian PKA‐RI‐specific AKAP with cytosolic localization, SPHKAP is a very promising model for studying the function of the less explored cytosolic PKA‐RI signaling nodes.     

Deciphering Genetic Alterations of Taiwanese Patients with Pancreatic Adenocarcinoma through Targeted Sequencing

Pancreatic adenocarcinoma (PAC) is the 8th leading cause of cancer-related deaths in Taiwan, and its incidence is increasing. The development of PAC involves successive accumulation of multiple genetic alterations. Understanding the molecular pathogenesis and heterogeneity of PAC may facilitate personalized treatment for PAC and identify therapeutic agents. We performed tumor-only next-generation sequencing (NGS) with targeted panels to explore the molecular changes underlying PAC patients in Taiwan. The Ion Torrent Oncomine Comprehensive Panel (OCP) was used for PAC metastatic lesions, and more PAC samples were sequenced with the Ion AmpliSeq Cancer Hot Spot (CHP) v2 panel. Five formalin-fixed paraffin-embedded (FFPE) metastatic PAC specimens were successfully assayed with OCP, and KRAS was the most prevalent alteration, which might contraindicate the use of anti-EGFR therapy. One PAC patient harbored a FGFR2 p. C382R mutation, which might benefit from FGFR tyrosine kinase inhibitors. An additional 38 samples assayed with CHP v2 showed 100 hotspot variants, collapsing to 54 COSMID IDs. The most frequently mutated genes were TP53, KRAS, and PDGFRA (29, 23, 10 hotspot variants), impacting 11, 23, and 10 PAC patients. Highly pathogenic variants, including COSM22413 (PDGFRA, FATHMM predicted score: 0.88), COSM520, COSM521, and COSM518 (KRAS, FATHMM predicted score: 0.98), were reported. By using NGS with targeted panels, somatic mutations with therapeutic potential were identified. The combination of clinical and genetic information is useful for decision making and precise selection of targeted medicine.     

New approach for simultaneous enhancement of anticorrosive and mechanical properties of coatings: Application of water repellent nano CaCO3–PANI emulsion nanocomposite in alkyd resin

New alkyd coatings were prepared by addition of water-based polyaniline–4% CaCO₃ (PAC) nanocomposites into alkyd resin. Pure polyaniline (PANI) and PAC were synthesized using ultrasound assisted emulsion polymerization and added to alkyd resin to form nanocomposite coating. Nano CaCO₃ was added in different percentage ranging from 0% to 8% of monomer during the synthesis of polyaniline. XRD and TEM reveals that water repellent nano CaCO₃ is thoroughly dispersed in PANI matrix. The effect of PANI and PAC nanocomposite on mechanical and anticorrosion performance of alkyd coating was evaluated. An electrochemical measurement (Tafel Plots) shows that corrosion current I_corr was decreased from 0.89 to 0.03 μA/cm², when PAC nanocomposite was added to neat coatings. Positive shift of E_corr. also indicates that PAC nanocomposite acts as an anticorrosive additive to alkyd coating. Presence of water repellant nano CaCO₃ in PAC nanocomposite has exhibited dual effect, such as improvement in mechanical and anticorrosion properties. The experimental results have shown superiority of PAC nanocomposite over PANI when PAC nanocomposite added to alkyd coatings.     

Regeneration of PAC saturated by bisphenol A in PAC/TiO2 combined photocatalysis system

This study investigated a dual function system combining powdered activated carbon (PAC) and TiO₂ for the removal of trace organics together with the in-situ regeneration of PAC. The combined system with PAC adsorption and TiO₂ photo-oxidation for in-situ regeneration of the PAC was studied as a batch process. Bisphenol A (BPA), an endocrine disrupting compound present at low concentration levels, was used as a model compound. When UV light and 0.5 l min^− 1 of oxygen were introduced to the PAC/TiO₂ batch system, the removal of BPA was 2.3 to 3.1 times faster than that of neat TiO₂ oxidation in the pH range of 4 to 10. However, mass transfer of the adsorbed BPA by diffusion from the PAC to oxidation sites on the surface of the TiO₂ was found to be limited because PAC has a strong affinity to adsorb BPA. During in-situ regeneration of PAC by TiO₂ photo-oxidation at pH 7 for 6 h, the removal of BPA from the PAC which was fully saturated with BPA was about 50%. The regeneration of the PAC was improved by increasing the UV-irradiation time (4 h to 12 h) and the light intensity (0.13 mW cm^− 2 to 0.425 mW cm^− 2), but it was not enhanced by increasing temperature, operating at basic conditions, or adding H₂O₂. The results suggest that a process with in-situ regeneration of PAC by TiO₂ oxidation may be feasible.     

Operation of Membrane Bioreactor with Powdered Activated Carbon Addition

Abstract

The effect of powdered activated carbon (PAC) addition to the activated sludge (AS) in a membrane bioreactor (MBR) has been investigated. The long term nature of the tests allowed the PAC to gradually incorporate into the biofloc forming biologically activated carbon (BAC). One series of tests involved 4 bench scale (2 L) MBRs operated at sludge retention times (SRTs) of 30 days with PAC inventories of 0, 1, 3 and 5 g/L and steady state biomass concentrations of 12.0±1.0 g/L. The characteristics of the mixed liquors (MLSS) from the 4 reactors were compared. Short term filtration tests, including measurement of specific cake resistance (SCR), flux decline profile, and irreversible fouling resistance in an unstirred cell and “sustainable” flux (by monitoring transmembrane pressure (TMP) rise) in a crossflow cell all showed better filtration performance for the MLSS with BAC compared with the AS alone. In terms of SCR and flux decline profile the 1 g/L PAC addition performed best, but in terms of minimizing irreversible membrane fouling and maximizing “sustainable” flux the 5 g/L PAC was best. All 4 systems showed lower total organic carbon (TOC) in the permeate compared to the bioreactors, but the lowest permeate TOC (and the best removal) was for the highest PAC loading.

The benefit of PAC addition was confirmed in a second series of tests with two 20 L MBRs with submerged hollow fibers, one operated without PAC, the MBR(AS), and the other with 5 g/L PAC, the MBR(BAC). For an SRT of 30 days (which involved 3.3% sludge wastage per day and 3.3% new PAC addition per day) and a fixed flux of 21 L/m²hr the MBR(AS) showed a TMP rise of about 2.4 kPa/day whereas the MBR(BAC) showed a rise of only 0.8 kPa/day. However when the MBRs were operated without wastage the performance of the MBR(BAC) was worse than the MBR(AS). Thus the improved performance of the MBR(BAC) requires regular replenishment of aged BAC with fresh PAC.     

Quorum Sensing in the Squid-Vibrio Symbiosis

Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization.     

Development of amine–acid cured Annona squamosa oil epoxy anticorrosive polymeric coatings

Forecasts for exhaustion of depleting petroleum resources in the years to come and escalating prices of petro-based chemicals, advocate the utilization of monomers/polymers derived from sustainable resources as an alternative. Oils of certain seeds may hold considerable promise as a source of unsaturated hydrocarbon, an excellent starting material for epoxidation and subsequent polymer production. Seeds of Annona squamosa (oil content 42–45%), go as a natural waste. Oil obtained from these seeds contains good amount of unsaturation; however, it has not been reported to be epoxidised, yet. Thus, epoxidation of A. squamosa oil (AOE) has been carried out in our effort to utilize a sustainable resource through the development of an anticorrosive coating material. AOE was further cured with different curing agent systems (ethylenediamine/phthalic acid (EDA–PA), 1,3-propanediamine/phthalic acid (PDA–PA), ethylenediamine/adipic acid (EDA–AA), 1,3-propanediamine/adipic acid (PDA–AA), p-phenylenediamine/adipic acid (PhDA–AA). AOE and AOE curing agent systems were subjected to structural elucidation by spectroscopic techniques (IR and ¹H NMR) and physico-chemical characterization (refractive index, specific gravity, iodine value, saponification value, hydroxyl value) involving standard methods. Thermal stability of these resins was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Coatings of oil epoxy curing agent combinations prepared on Fe- and Al-alloys (mild steel and aluminium-24345) were subjected to physico-mechanical and anticorrosive tests in various corrosive media (water, saline water, acid and alkali) along with abrasion and steam resistance, light fastness, water vapour transmission, gloss, salt fog and humidity tests. These systems apprise satisfactory performance under different corrosive environments. The approach offers an alternate way for resource utilization and overcomes the drawbacks (poor load-bearing capacity and hardness) of oil epoxy-based coatings.     

Monitoring Photosynthetic Activity in Microalgal Cells by Raman Spectroscopy with Deuterium Oxide as a Tracking Probe

Microalgae offer great potential for the production of biofuel, but high photosynthetic activity is demanded for the practical realisation of microalgal biofuels. To this end, it is essential to evaluate the photosynthetic activity of single microalgal cells in a heterogeneous population. In this study, we present a method to monitor the photosynthetic activity of microalgae (in particular Euglena gracilis, a microalgal species of unicellular, photosynthetic, flagellate protists as our model organism) at single-cell resolution by Raman spectroscopy with deuterium from deuterium oxide (D₂O) as a tracking probe. Specifically, we replaced H₂O in culture media with D₂O up to a concentration of 20 % without disturbing the growth rate of E. gracilis cells and evaluated C−D bond formation as a consequence of photosynthetic reactions by Raman spectroscopy. We used the probe to monitor the kinetics of the C−D bond formation in E. gracilis cells by incubating them in D₂O media under light irradiation. Furthermore, we demonstrated Raman microscopy imaging of each single E. gracilis cell to discriminate deuterated cells from normal cells. Our results hold great promise for Raman-based screening of E. gracilis and potentially other microalgae with high photosynthetic activity by using D₂O as a tracking probe.     

Spontaneous Vesicle Formation in Mixtures of Quaternary Ammonium Compounds with Carbamate and Sodium Dodecylbenzene Sulfonate

Spontaneous vesicles formation in the aqueous mixtures of 2,3‐bis (dodecylcarbamoyloxy)‐N, N‐dimethyl‐N‐(2‐hydroxyalkyl) propyl ammonium chloride (C₁₂PAC) and sodium dodecylbenzene sulfonate at different mixing molar ratios have been investigated. The characterizations are demonstrated by electrical conductivity measurements, dynamic light scattering and zeta (ζ) potential measurements. The ζ‐potential results indicate the C₁₂PAC/SDBS systems are stable. The shapes of the catanionic vesicles are observed by negative‐staining transmission electronic microscopy. Meanwhile, from the viewpoint of molecular geometry structure, the electrostatic interaction between anionic and cationic molecules is regarded as the main driving force for spontaneous formation of vesicles.     

Immobilized titanium dioxide/powdered activated carbon system for the photocatalytic adsorptive removal of phenol

Titanium dioxide (TiO₂) and powdered activated carbon (PAC) were fabricated via a layer by layer arrangement on a glass plate using a dip-coating technique for the photocatalytic-adsorptive removal of phenol. Thinner TiO₂ layer coated on PAC sub-layer has larger surface area and better phenol removal than the thicker TiO₂ layer. The system obeyed the Langmuir isotherm model, which exhibited a homogeneous and monolayer adsorption with a maximum capacity of 27.8 mg g^-1. The intra-particle diffusion was the rate-limiting step as the linear plot crossed the origin, while the adsorption was unfavorable at elevated temperature. Under light irradiation, the TiO₂/PAC system removed phenol two-times more effectively than the TiO₂ monolayer due to the synergistic effect of photocatalysis by TiO₂ top layer and adsorption by PAC sub-layer. The COD removal of phenol was rapid for 10mg L^-1 of concentration and under solar light irradiation. It was shown that the PAC sub-layer plays a significant role in the total removal of phenol by providing the adsorption sites and slowing down the recombination rate of charge carriers to improve the TiO₂ photocatalytic oxidation performance.     

Clarification of liquids using filter aids Part III. Cake Resistance in surface filtration

The specific cake resistance of mixed cakes was studied in filter-aid filtration using pre-coat and body feed. The influence of the relative amounts (weight ratio c/a) and the properties of the filter aid and the impurity on the specific cake resistance (r) was determined. An exponential relationship between r and c/a was derived, based on the blocking behaviour of a filter cloth. This relationship was confirmed in the filtration of protein flocs from turbid beer, and yeast, iron hydroxide flocs and monosize polystyrene particles from water. Based on this law, an optimum body-feed dosage can be predicted in order to obtain a minimum cake resistance. In beer filtration special attention has been paid to the compressibility of the mixed cakes.     

SCM-198 Ameliorates Cognitive Deficits,Promotes Neuronal Survival and Enhances CREB/BDNF/TrkB Signaling without Affecting Aβ Burden in AβPP/PS1 Mice

SCM-198 is an alkaloid found only in Herba leonuri and it has been reported to possess considerable neuroprotective effects in animal models of ischemic stroke, Parkinson’s disease and Alzheimer’s disease (AD). In this study, we demonstrated for the first time that 3-month oral SCM-198 treatment could significantly improve both recognition and spatial memory, inhibit microgliosis and promote neuronal survival in amyloid-β protein precursor and presenilin-1(AβPP/PS1) double-transgenic mice without affecting amyloid-β (Aβ) burden. In addition, decreases in cAMP-response element-binding protein (CREB) phosphorylation, brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) phosphorylation were attenuated by SCM-198 both in vivo and in primary cortical neurons, which could be blocked by protein kinase A (PKA) inhibitors, suggesting the involvement of upstream PKA in enhancing the BDNF/TrkB/CREB signaling by SCM-198. Our results indicate that SCM-198, a drug that could promote neuronal survival and enhance BDNF/TrkB/CREB signaling, has beneficial effects on behavioral and biochemical alterations without affecting Aβ burden in AβPP/PS1 mice and might become a potential drug candidate for AD treatment in the future.     

Photocatalysis assisted by activated-carbon-impregnated magnetite composite for removal of cephalexin from aqueous solution

The simultaneous presence of antibiotics and bacteria in aqueous media has been recognized as an environmental threat, due to the enhancement of antibiotic resistance of bacteria. We synthesized an activated carbon impregnated magnetite composite (PAC/Fe3O4) and used it for removal of cephalexin (CEX) from aqueous solution via UV system. A series of batch experiments was carried out under various experimental conditions such as pH of solution (3–11), contact time (0–120 min), catalyst dosages (0.1–2 g/L) and initial CEX concentrations (10, 25, 50 and 100 mg/L). Some common isotherm models were used for study of CEX adsorption and finding the best model. In addition, kinetic studies of CEX photocatalytic removal were performed by fitting the experimental data on first-order and second-order models. Results of comparative studies showed that UV+PAC/Fe₃O₄ and UV+TiO₂ systems, compared to UV/Fe3O4, naked Fe₃O₄, PAC/Fe₃O₄ and UV only, had more capability of removing CEX from aqueous solution, indicating PAC/Fe₃O₄ is effectively catalyzed by UV light. Furthermore, increasing catalyst dosages and decreasing initial CEX concentrations led to the enhancing photocatalytic removal of CEX from solution. The obtained results of kinetic studies also represent that among the studied models, second-order model with significant coefficient of correlation (R²) had higher ability than first-order model to fit the data of CEX removal. Finally, the findings of reusability tests, showed that the applied catalyst would be applicable for CEX removal, even after five consecutive cycles.     

Synergistic and Antagonistic Action of Phytochrome (Phy) A and PhyB during Seedling De-Etiolation in Arabidopsis thaliana

It has been reported that Arabidopsis phytochrome (phy) A and phyB are crucial photoreceptors that display synergistic and antagonistic action during seedling de-etiolation in multiple light signaling pathways. However, the functional relationship between phyA and phyB is not fully understood under different kinds of light and in response to different intensities of such light. In this work, we compared hypocotyl elongation of the phyA-211 phyB-9 double mutant with the wild type, the phyA-211 and phyB-9 single mutants under different intensities of far-red (FR), red (R), blue (B) and white (W) light. We confirmed that phyA and phyB synergistically promote seedling de-etiolation in B-, B plus R-, W- and high R-light conditions. The correlation of endogenous ELONGATED HYPOCOTYL 5 (HY5) protein levels with the trend of hypocotyl elongation of all lines indicate that both phyA and phyB promote seedling photomorphogenesis in a synergistic manner in high-irradiance white light. Gene expression analyses of RBCS members and HY5 suggest that phyB and phyA act antagonistically on seedling development under FR light.