Fabrication and Investigation of Deformable Rubber-Carbon Nanotube-Glue Gel-Based Impedimetric and Capacitive Tactile Sensors for Pressure and Displacement Measurements.

Carbon nanotube-glue composite gel-based surface-type elastic sensors with a cylindrical shape deformable (flexible) metallic body were fabricated for tactile pressure and compressive displacement sensing. The fabrication of the sensors was performed using the rubbing-in technique. The effect of the pressure and the compressive displacement on the capacitance and the impedance of the sensors were investigated at various frequencies (in the range of 1 kHz to 200 kHz). It was found that under the effect of pressure from 0 to 9 g/cm2, the capacitance increased by 1.86 and 1.78 times, while the impedance decreased by 1.84 and 1.71 times at the frequencies of 1 kHz to 200 kHz, respectively. The effect of displacement on the impedance and the capacitance of the device was also investigated at various frequencies from 1 kHz to 200 kHz. The results showed that under the effect of compressive displacement up to 25 µm, the impedance of the sensors decreased on average by 1.19 times, while the capacitance increased by 1.09 times, accordingly. The frequency response of the displacement sensor showed that it matched with the low-pass filter. The obtained results are explained based on changes in the shape and geometrical parameters of the cylindrical-shaped conductive body. These results have also been explained on the basis of the distance between the conductive plates of the capacitive sensors during compression, which takes place under the effect of applied pressure or displacement. Moreover, the design of the sensors is simple and easy to fabricate, and their use is also earthy. The fabricated sensors have great potential for commercialization.

Sulfonamide Derived Esters: Synthesis, Characterization, Density Functional Theory and Biological Evaluation through Experimental and Theoretical Approach.

A series of new solid esters was synthesized by using greener chemistry strategy involving simple reaction of an alcohol with sulfonamide ligand. Characterization study of these methyl (1), ethyl (2) isopropyl (3) and n-butyl (4) ester of 4-((4-chlo-rophenylsulfonamido)methyl)cyclohexanecarboxylic acid was done by using FTIR, NMR mass spectrometry and X-ray crystallography. The compounds were optimized with Gaussian software according to basis set B3LYP/6-31G(d,p) and their different parameters related to structure were calculated. Furthermore, all compounds of the series were screened for their in vitro biological applications involving anti-bacterial (Chromohalobactor salixgens, Halomonas halofila, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Shiegella sonnei), anti-fungal (Aspergillus niger), anti-oxidant (DPPH scavenging activity) and enzyme inhibition (acetylcholine esterase and butyrylcholine esterase) study. Sulfonamide based esters were also docked against selected enzymes (AChE and BChE) using MOE software for their mode of binding. Results obtained from these biological evaluations showed that such compounds have potential against targeted activity.

Electrochemical detection of 2-nitrophenol using a heterostructure ZnO/RuO2 nanoparticle modified glassy carbon electrode.

A highly selective chemisensor for 2-nitrophenol detection was fabricated using ZnO/RuO2 nanoparticles (NPs) synthesized by impregnation method. The as-synthesized NPs were characterized through UV-vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDS), FTIR and X-ray diffraction (XRD). A glassy carbon electrode was modified with as-synthesized ZnO/RuO2 nanoparticles and utilized as a chemical sensor for the detection of 2-nitrophenol. The fabricated sensor exhibited excellent sensitivity (18.20 µA µM-1 cm-2), good reproducibility, short response time (8.0 s.), the lowest detection limit (52.20 ± 2.60 pM) and long-term stability in aqueous phase without interference effects. Finally, the fabricated sensor was validated as a 2-NP probe in various environmental water samples at room conditions.

Spasmolytic and Ca++ Channel Blocking Potential of Nepetolide: Isolated from Nepeta suavis.

Nepeta suavis is used in traditional medicine for treatment of abdominal spasm (colic). The tricyclic clerodane type diterpene, nepetolide, isolated for the first time from Nepeta suavis, was evaluated for Ca++ antagonist and antispasmodic activities. When studied in isolated rabbit jejunum, nepetolide caused concentration-dependent (0.03-100 µM) relaxation of spontaneous and high K+ (80 mM)-induced contractions, like that caused by verapamil, indicating that nepetolide exhibits spasmolytic activity, possibly mediated through Ca++ channel blocking action, which provides scientific explanation for the medicinal application of Nepeta suavis as an antispasmodic agent.

Synergistic geometric and electronic effects for electrochemical reduction of carbon dioxide using gold-copper bimetallic nanoparticles.

Highly efficient and selective electrochemical reduction of carbon dioxide represents one of the biggest scientific challenges in artificial photosynthesis, where carbon dioxide and water are converted into chemical fuels from solar energy. However, our fundamental understanding of the reaction is still limited and we do not have the capability to design an outstanding catalyst with great activity and selectivity a priori. Here we assemble uniform gold-copper bimetallic nanoparticles with different compositions into ordered monolayers, which serve as a well-defined platform to understand their fundamental catalytic activity in carbon dioxide reduction. We find that two important factors related to intermediate binding, the electronic effect and the geometric effect, dictate the activity of gold-copper bimetallic nanoparticles. These nanoparticle monolayers also show great mass activities, outperforming conventional carbon dioxide reduction catalysts. The insights gained through this study may serve as a foundation for designing better carbon dioxide electrochemical reduction catalysts.

Acetylcholinesterase biosensor based on a gold nanoparticle-polypyrrole-reduced graphene oxide nanocomposite modified electrode for the amperometric detection of organophosphorus pesticides.

A nanohybrid of gold nanoparticles, polypyrrole, and reduced graphene oxide sheets (named as Au-PPy-rGO) was achieved by electrochemical deposition of reduced graphene oxide with pyrrole and the introduction of gold nanoparticles. Acetylcholinesterase (AChE) was further encapsulated in a silica matrix and immobilized on the Au-PPy-rGO nanocomposite by co-deposition with (NH4)2SiF6. The presence of PPy helped to avoid the aggregation of rGO caused by van der Waals interactions between individual sheets and significantly increased the surface area of the modified electrode. The obtained Au-PPy-rGO nanocomposite not only showed excellent conductivity but also exhibited a high electrocatalytic activity and specific affinity for thiocholine, the hydrolysis product of the enzyme, and thus an improved detection sensitivity. Since AChE molecules were protected by the circumambient silica matrix, which provided a biocompatible environment and facilitated mass transport, the fabricated AChE biosensor displayed high stability and excellent activity together with a fast response to organophosphorus pesticides. Under optimum conditions, the biosensor led to the rapid and sensitive detection of paraoxon-ethyl from 1.0 nM to 5 µM with a detection limit of 0.5 nM.

Synthesis of novel indenoquinoxaline derivatives as potent α-glucosidase inhibitors.

A series of new N-(11H-Indeno[1,2-b]quinoxalin-11-ylidene)benzohydrazide derivatives (3a-3p) were synthesized and evaluated for their α-glucosidase inhibitory activity. The synthesized compounds 3d, 3f, 3g, 3k, 3n, 3p and 4 showed significant α-glucosidase inhibitory activity as compared to acrabose, a standard drug used to treat type II diabetes. Structures of the synthesized compounds were determined by using FT-IR, (1)H NMR, (13)C NMR, mass spectrometry and elemental analysis techniques.

Deuterium isotope effect on bulk heterojunction solar cells. Enhancement of organic photovoltaic performances using monobenzyl substituted deuteriofullerene acceptors.

A series of novel monobenzyl-substituted deuteriofullerenes (BnDCs) were synthesized efficiently through Co-catalyzed selective monofunctionalization of C60. Bulk heterojunction solar cells, based on poly(3-hexylthiophene) as the donor and BnDCs as the acceptors, exhibited higher photovoltaic performances as compared to the corresponding protonated BnHCs devices.

Bioactive C15 acetogenins from the red alga Laurencia obtusa.

The petroleum ether extract of the red alga Laurencia obtusa afforded three new C(15) acetogenins (cyclic ether enyne): (12Z)-cis-maneonene-D (1), (12E)-cis-maneonene-E (2), and (12Z)-trans-maneonene-C (3), along with one known cis-maneonene-A (4). Blood neutrophils were prepared, cultured, and incubated for 24, 48, and 72 h in medium with and without isolated compounds. Blood neutrophils were prepared, cultured, and incubated for 24, 48 and 72 h in medium with and without the isolated compounds. Both morphology and DNA fragmentation methods assessed the percentage of neutrophils apoptosis in each culture. In the present study, several observations have been made concerning the apoptosis-inducing or inhibiting effect of 1 and 2. Both compounds had no inhibition of apoptosis but apoptosis was enhanced significantly by aging. However, 1 stimulated apoptosis of normal only at the initial 24 h. After that there was no significant difference in apoptosis with or without compound 1, while 2 stimulated apoptosis at all the times. The apoptosis induced by these two compounds was demonstrated by DNA fragmentation assay and microscopic observation. These observations suggest that compounds 1 and 2 may be involved in regulation of programmed death in the initiation and propagation of inflammatory responses.

Synthesis, molecular conformation, vibrational and electronic transition, isometric chemical shift, polarizability and hyperpolarizability analysis of 3-(4-methoxy-phenyl)-2-(4-nitro-phenyl)-acrylonitrile: a combined experimental and theoretical analysis.

This work presents the synthesis and characterization of a novel compound, 3-(4-methoxy-phenyl)-2-(4-nitro-phenyl)-acrylonitrile (abbreviated as 3-(4MP)-2-(4-NP)-AN, C(16)H(12)N(2)O(3)). The spectroscopic properties of the compound were examined by FT-IR, UV-vis and NMR ((1)H and (13)C) techniques. FT-IR spectrum in solid state was observed in the region 4000-400 cm(-1). The UV-vis absorption spectrum of the compound which dissolved in chloroform was recorded in the range of 200-800 nm. The (1)H and (13)C NMR spectra were recorded in CDCl(3) solution. To determine lowest-energy molecular conformation of the title molecule, the selected torsion angle is varied every 10° and molecular energy profile is calculated from 0° to 360°. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP/6-31G(d,p) basis set. The dipole moment, linear polarizability and first hyperpolarizability values were also computed using the same basis set. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The HOMO and LUMO analysis were used to elucidate information regarding charge transfer within the molecule. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR spectrum. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. Comparison of the calculated frequencies, NMR chemical shifts, absorption wavelengths with the experimental values revealed that DFT and TD-DFT method produce good results. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the title compound can be used as a good nonlinear optical material. The thermodynamic properties of the studied compound at different temperatures were calculated, revealing the correlations between standard heat capacity, standard entropy, standard enthalpy changes and temperatures.

(2Z)-2-(4-Methyl-phen-yl)-3-(2-naphth-yl)prop-2-enenitrile.

In the title compound, C(20)H(15)N, the dihedral angle between the naphthalene and benzene rings is 60.30 (16)°. The crystal packing features very weak inter-molecular C-H⋯π inter-actions.

2-(1,3-Benzothia-zol-2-ylimino-meth-yl)-2-naphthol.

In the title mol-ecule, C(18)H(12)N(2)OS, the dihedral angle between the two fused-ring systems is 7.2 (1)°. The hydr-oxy group forms an intra-molecular hydrogen bond with the imino group.

Diethyl 3H-naphtho[2,1-b]pyran-2,3-dicarboxyl-ate.

The sp(3)-hybridized methine C atom in the title compound, C(19)H(18)O(5), lies out of the mean plane of the remaining 13 atoms of the naphthopyran fused-ring system by 0.571 (1) Å, and its H atom occupies a pseudo-equatorial site.

(E,E)-2-[3,4-Bis(4-methyl-benzyl-idene)-5-oxotetra-hydro-furan-2-yl-idene]propane-dinitrile.

In the title mol-ecule, C(23)H(16)N(2)O(2), the two exocyclic C=C bonds bearing the tolyl groups have an E configuration and the beznene rings are oriented at 22.1 (1) and 24.8 (1)° with respect to the mean plane of the atoms of the furan ring.

4-(2-Methoxy-benzyl-idene)-2-phenyl-1,3-oxazol-5(4H)-one.

The title mol-ecule, C(17)H(13)NO(3), adopts a Z configuration about the central olefinic bond. The 2-phenyl ring is almost coplanar with the plane of the oxazolone ring system, making a dihedral angle of 2.03 (11)°. The crystal structure is stabilized by π-π inter-actions between the oxazolone ring and phenyl ring of a neighbouring mol-ecule [centroid-centroid distance = 3.550 (3)Å], and by two weak inter-molecular C-H⋯π inter-actions. In addition, the crystal structure exhibits one weak intra-molecular C-H⋯N hydrogen bond.

2-benzenesulfonamidobenzoic Acid.

In the title compound, C(13)H(11)NO(4)S, the dihedral angle between the planes of the benzene ring and the carboxyl group is 13.7 (1)°. The mol-ecular structure contains intra-molecular N-H⋯O and C-H⋯O hydrogen-bonding inter-actions, while the crystal packing is stabilized by C-H⋯O and O-H⋯O hydrogen bonds and C-H⋯π inter-actions. The O-H⋯O hydrogen bonds form a cyclic dimer, with graph-set motif R(2) (2)(8), about a centre of symmetry.

(E)-2-Cyano-3-[4-(dimethyl-amino)phen-yl]-N-phenyl-prop-2-enamide.

In the title compound, C(18)H(17)N(3)O, the dihedral angle between the phenyl and benzene rings is 11.22 (14)°. Apart from the methyl H atoms, the mol-ecule is close to planar, with a maximum deviation of 0.145 (3) Å. Intra-molecular C-H⋯O and C-H⋯N inter-actions occur. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds occur, resulting in an R(2) (2)(12) ring motif. Further C-H⋯N and C-H⋯O bonds generate R(1) (2)(7) and R(2) (2)(22) motifs and a C-H⋯π inter-action also occurs.

(2E,2'E)-1,1'-Bis(2,5-dimethyl-3-thien-yl)-3,3'-(p-phenyl-ene)diprop-2-en-1-one.

In the title bis-chalcone, C(24)H(22)O(2)S(2), the -C(O)CH=CH-C(6)H(4)-CH=CHC(O)- portion is planar (r.m.s. deviation = 0.04 Å); one thienyl ring is aligned at 8.8 (1)° with respect to this fragment, whereas the other is aligned at 21.3 (1)°.

(E)-4-(2,5-Dimethoxy-benzyl-idene)-2-phenyl-1,3-oxazol-5(4H)-one.

The central aza-lactone ring in the title compound, C(18)H(15)NO(4), is planar (r.m.s. deviation 0.05, 0.12 Å) in both independent mol-ecules comprising the asymmetric unit. The benzyl-idene substituent is coplanar with this ring [dihedral angle between the planes = 1.8 (1)° in the first mol-ecule and 2.8 (1)° in the second], as is the phenyl substitutent [dihedral angle between rings = 4.6 (1) and 9.7 (1)°, respectively].

5-[3-(2,5-Dimethoxy-phen-yl)prop-2-enyl-idene]-1,3-diethyl-2-thioxohexa-hydro-pyrimidine-4,6-dione.

1,3-Diethyl-2-thio-barbituric acid reacts with 2,5-dimethoxy-benzaldehyde to form the title Knoevenagel product, C(19)H(22)N(2)O(4)S. In the compound, the two six-membered rings at either end of the three-membered -CHCHCH- chain are nearly coplanar with this fragment (r.m.s. deviation of the two six-membered rings and the three chain atoms = 0.08 Å).