Topological alternate centrality measure capturing drug targets in the network of MAPK pathways

A new centrality of the nodes in the network is proposed called alternate centrality, which can isolate effective drug targets in the complex signalling network. Alternate centrality metric defined over the network substructure (four nodes – motifs). The nodes involving in alternative activation in the motifs gain in metric values. Targeting high alternative centrality nodes hypothesised to be destructive free to the network due to their alternative activation mechanism. Overlapping and crosstalk among the gene products in the conserved network of MAPK pathways selected for the study. In silico knock‐out of high alternate centrality nodes causing rewiring in the network is investigated using MCF‐7 breast cancer cell line‐based data. Degree of top alternate centrality nodes lies between the degree of bridging and pagerank nodes. Node deletion of high alternate centrality on the centralities such as eccentricity, closeness, betweenness, stress, centroid and radiality causes low perturbation. The authors identified the following alternate centrality nodes ERK1, ERK2, MEKK2, MKK5, MKK4, MLK3, MLK2, MLK1, MEKK4, MEKK1, TAK1, P38alpha, ZAK, DLK, LZK, MLTKa/b and P38beta as efficient drug targets for breast cancer. Alternate centrality identifies effective drug targets and is free from intertwined biological processes and lethality.Inspec keywords: biochemistry, molecular biophysics, cellular biophysics, cancer, drugs, genetics, biomedical materialsOther keywords: MAPK pathways, complex signalling network, pagerank nodes, node deletion, drug targets, MCF‐7 breast cancer cell line‐based data, cellular mechanisms, ERK1 nodes, ERK2 nodes, MEKK2 nodes, MKK5 nodes, MKK4 nodes, MLK3 nodes, MLK2 nodes, MLK1 nodes, MEKK4 nodes, MEKK1 nodes, TAK1 nodes, P38alpha nodes, ZAK nodes, DLK nodes, LZK nodes, MLTKa/b nodes, P38beta nodes     

Kinetics of the removal of mono-chlorobenzene vapour from waste gases using a trickle bed air biofilter

The performance of a trickle bed air biofilter (TBAB) in the removal of mono-chlorobenzene (MCB) was evaluated in concentrations varying from 0.133 to 7.187 g m(-3) and at empty bed residence time (EBRT) varying from 37.7 to 188.52 s. More than 90% removal efficiency in the trickle bed air biofilter was achieved for the inlet MCB concentration up to 1.069 g m(-3) and EBRT less than 94.26 s. The trickle bed air biofilter was constructed with coal packing material, inoculated with a mixed consortium of activated sludge obtained from sewage treatment plant. The continuous performance of the removal of MCB in the trickle bed air biofilter was monitored for various gas concentrations, gas flow rates, and empty bed residence time. The experiment was conducted for a period of 75 days. The trickle bed air biofilter degrading MCB with an average elimination capacity of 80 g m(-3) h(-1) was obtained. The effect of starvation was also studied. After starvation period of 8 days, the degradation was low but recovered within a short period of time. Using macrokinetic determination method, the Michaelis-Menten kinetic constant K(m) and maximum reaction rate, r(max) evaluated as 0.121 g m(-3) s(-1) and 7.45 g m(-3), respectively.     

Hydrotreating of Heavy Gas Oil Derived from Athabasca Bitumen Over Co–Mo/γ-Al2O3 Catalyst Prepared by Sonochemical Method

Co–Mo/γ-Al₂O₃ oxide containing 9.8 wt% Mo and 2.9 wt% Co was prepared by high-intensity ultrasonic irradiation of Mo(CO)₆, Co₂(CO)₈, and γ-Al₂O₃ in decahydronapthalene under air flow. The oxidic Co–Mo catalyst thus formed was characterized by elemental analysis, BET N₂ adsorption and XRD. The surface sites on the sulfided Co–Mo/γ-Al₂O₃ catalyst were characterized by infrared spectroscopy of CO adsorption. Hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) activities were evaluated for heavy gas oil derived from Athabasca bitumen in a trickle bed reaction system using the following conditions: temperatures ranging from 370 to 400 °C, a pressure of 8.8 MPa, a liquid hourly space velocity of 1 h⁻¹, and a H₂/feed ratio of 600 ml/ml. The dispersion, nature of active sites and hydrotreating activity of this catalyst were compared with the conventionally prepared Co–Mo/γ-Al₂O₃ catalyst containing similar wt% of Mo and Co. The Co–Mo catalyst prepared by sonochemical method has higher HDN and HDS rate constants than the conventional catalyst due to an improved dispersion of MoS₂.     

Hydrotreating of gas oil on SBA-15 supported NiMo catalysts

The siliceous and the metal substituted (B or Al)-SBA-15 molecular sieves were used as a support for NiMo hydrotreating catalysts (12 wt.% Mo and 2.4 wt.% Ni). The supports were characterized by X-ray diffraction (XRD), scanning electron microscopy and N₂ adsorption–desorption isotherms. The SBA-15 supported NiMo catalysts in oxide state were characterized by BET surface area analysis and XRD. The sulfided NiMo/SBA-15 catalysts were examined by DRIFT of CO adsorption and TPD of NH₃. The HDN and HDS activities with bitumen derived light gas oil at industrial conditions showed that Al substituted SBA-15 (Al-SBA-15) is the best among the supports studied for NiMo catalyst. A series of NiMo catalysts containing 7–22 wt.% Mo with Ni/Mo weight ratio of 0.2 was prepared using Al-SBA-15 support and characterized by BET surface area analysis, XRD and temperature programmed reduction and DRIFT spectroscopy of adsorbed CO. The DRIFT spectra of adsorbed CO showed the presence of both unpromoted and Ni promoted MoS₂ sites in all the catalysts, and maximum “NiMoS” sites concentration with 17 wt.% of Mo loading. The HDN and HDS activities of NiMo/Al-SBA-15 catalysts were studied using light gas oil at temperature, pressure and WHSV of 370 °C, 1300 psig and 4.5 h⁻¹, respectively. The NiMo/Al-SBA-15 catalyst with 17 wt.% Mo and 3.4 wt.% of Ni is found to be the best catalyst. The HDN and HDS activities of this catalyst are comparable with the conventional Al₂O₃ supported NiMo catalyst in real feed at industrial conditions.     

Effect of EDTA on hydrotreating activity of CoMo/γ-Al2O3 catalyst

γ-Al₂O₃ supported Co (0–4.5 wt%) Mo (9.0 wt%) sulfide catalysts were prepared in the presence and the absence of ethylenediaminetetraacetic acid (EDTA). The hydrodenitrogenation (HDN) activity of these catalysts was studied in the model reaction of 2,6-dimethylaniline (DMA) at 300 °C under 4 MPa. The CoMo/Al₂O₃ catalysts prepared with the EDTA showed higher HDN of DMA than those prepared without EDTA. The maximum of 36% increase in rate constant of HDN of DMA was observed over the catalyst with 3% Co prepared using EDTA. The FT-IR spectroscopy of adsorbed CO on CoMo catalysts showed that EDTA addition promoted the formation of catalytically active “CoMoS” phase as evidenced from increases in intensity of band at 2070 cm⁻¹, which is maximum for 3% Co loaded catalysts. The HDN and hydrodesulfurization (HDS) activity of 3% Co loaded catalyst prepared using EDTA was tested and compared with those catalyst prepared without EDTA in a trickle bed reactor using heavy gas oil derived from Athabasca bitumen in the temperature range 370–400 °C and 8.8 MPa. Improved HDN and HDS conversion of heavy gas oil was obtained for the catalyst prepared with EDTA.     

Realization of tunable RC-active oscillators using grounded capacitors and voltage amplifiers

A systematic procedure is given to generate a set of tunable RC oscillators, each using two finite gain voltage controlled voltage sources, three resistors and two grounded capacitors. These realizations are shown to be minimal with respect to passive and active elements under the constraint that (one end of) all the capacitors remain grounded. The set consists of four oscillators and is shown to be complete, that is, no additional oscillator circuit can be generated under the given assumptions. A simple approach is then introduced for testing the structures for latch up behaviour. This approach also suggests a way of redesigning the oscillator circuits to render them free of latch up problems, if they exist. Experimental results are found to be in good agreement with the theory.     

2D-titanium carbide (MXene) based selective electrochemical sensor for simultaneous detection of ascorbic acid,dopamine and uric acid

Two-dimensional (2D) titanium carbide (MXene) nanosheets exhibited excellent conductivity,flexibility,high volumetric capacity,hydrophilic surface,thermal stability,etc.So,it has been exploited in various applications.Herein,we report synthesis of mixed phase 2D MXene as a catalytic material for simultaneous detection of important biomolecules such as ascorbic acid (AA),dopamine (DA) and uric acid (UA),Crystalline structure,surface morphology and elemental composition of mixed phase titanium carbide (Ti-C-Tx) MXene (Tx =-F,-OH,or-O) nanosheets were confirmed by X-ray diffraction (XRD),Raman spectroscopy,high-resolution transmission electron microscopy (HR-TEM),high-resolution scanning electron microscopy (HR-SEM) and Energy-dispersive X-ray spectroscopy (EDS) mapping analysis.Furthermore,Ti-C-Tx modified glassy carbon electrode (GCE) was prepared and its electrochemical properties are studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV).It was found that Ti-C-Tx modified GCE (Ti-C-Tx/GCE) showed excellent electrocatalytic activity and separated oxidation peaks of important biomolecules such as AA (at 0.01 V),DA (at 0.21 V) and UA (at 0.33 V).Also,Ti-C-Tx/GCE sensor is enabled their simultaneous detection in physiological pH from 100 to 1000 μM for AA,0.5-50 μM for DA and 0.5-4 μM & 100-1500 μM for UA.The limit ofdetection's (LOD) was estimated as 4.6 μM,0.06 μM and 0.075 μM for AA,DA and UA,respectively.Moreover,real sample analysis indicated that spiked AA,DA and UA can be determined accurately by Ti-C-Tx/GCE with the recovery ratio in the range between 100.5％-103％ in human urine samples.The proposed Ti-C-Tx modified electrode exhibited good stability,selectivity and reproducibility as an electrochemical sensor for the detection ofAA,DA and UA molecules.     

Toward nanometer-scale optical photolithography: utilizing the near-field of bowtie optical nanoantennas

Optically resonant metallic bowtie nanoantennas are utilized as fabrication tools for the first time, resulting in the production of polymer resist nanostructures <30 nm in diameter at record low incident multiphoton energy densities. The nanofabrication is accomplished via nonlinear photopolymerization, which is initiated by the enhanced, confined optical fields surrounding the nanoantenna. The position, size, and shape of the resist nanostructures directly correlate with rigorous finite-difference time-domain computations of the field distribution, providing a nanometer-scale measurement of the actual field confinement offered by single optical nanoantennas. In addition, the size of the photoresist regions yields strong upper bounds on photoacid diffusion and resist resolution in SU-8, demonstrating a technique that can be generalized to the study of many current and yet-to-be-developed photoresist systems.     

Effect of phosphorus addition on the hydrotreating activity of NiMo/Al2O3 carbide catalyst

A series of phosphorus promoted γ-Al₂O₃ supported NiMo carbide catalysts with 0–4.5 wt.% P, 13 wt.% Mo and 2.5 wt.% Ni were synthesized and characterized by elemental analysis, pulsed CO chemisorption, BET surface area measurement, X-ray diffraction, near-edge X-ray absorption fine structure, DRIFT spectroscopy of CO adsorption and H₂ temperature programmed reduction. X-ray diffraction patterns and CO uptake showed the P addition to NiMo/γ-Al₂O₃ carbide, increased the dispersion of β-Mo₂C particles. DRIFT spectra of adsorbed CO revealed that P addition to NiMo/γ-Al₂O₃ carbide catalyst not only increases the dispersion of Ni-Mo carbide phase, but also changes the nature of surface active sites. The hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) activities of these P promoted NiMo/γ-Al₂O₃ carbide catalysts were performed in trickle bed reactor using light gas oil (LGO) derived from Athabasca bitumen and model feed containing quinoline and dibenzothiophene at industrial conditions. The P added NiMo/γ-Al₂O₃ carbide catalysts showed enhanced HDN activity compared to the NiMo/γ-Al₂O₃ catalysts with both the feed stocks. The P had almost no influence on the HDS activity of NiMo/γ-Al₂O₃ carbide with LGO and dibenzothiophene. P addition to NiMo/γ-Al₂O₃ carbide accelerated CN bond breaking and thus increased the HDN activity.