Hybrid LTA vehicle controllability as affected by buoyancy ratio

The zero and low speed controllability of heavy lift airships under various wind conditions as affected by the buoyancy ratio are investigated. A series of three hybrid LTA vehicls were examined, each having a dynamic thrust system comprised of four H-34 helicopters, but with buoyant envelopes of different volumes (and hence buoyancies), and with varying percentage of helium inflation and varying useful loads (hence gross weights). Buoyancy ratio, B, was thus examined varying from approximately 0.44 to 1.39. For values of B greater than 1.0, the dynamic thrusters must supply negative thrust (i.e. downward)

Organotin(IV) Derivatives of L-Cysteine and their in vitro Anti-Tumor Properties

The synthesis and characterization of the organotin compounds [(n-C4H9)2Sn(cys)] (1), [(C6H5)2Sn(cys)] (2), [(C6H5)3Sn(Hcys).(H2o)] (3), {[(CH3)2Sn(Kcys)2].2(H20)} (4), {[(n-C4H9)2Sn(Kcys)2].2(H20)} (5) and {[(C6H5)2Sn(Kcys)2].2(H20)} (6) (where H2cys = L-cysteine) are reported. The compounds have been characterized by elemental analysis and 1H-NMR, Uv-Vis, FT-IR and MOssbauer spectroscopic techniques. Attempted recrystallization of (2) in DMSO/methanol 2:1 solution yielded after several days unexpectedly the dimeric compound bis(tri-phenyltin)sulphide {[(C6H5)3Sn]2S} (7) which has been characterized by x-ray analysis. The structure of the parent complex (2) as well as the mechanism of the decomposition of cysteine are being further investigated. The in vitro anticancer activity of complexes (I)- (6), against human leukemia (HL60), human liver (Bel7402), human stomach (BGC823) and human cervix epithelial human carcinoma (Hela), nasopharyngeal carcinoma (KB) and lung cancer (PG) tumor cells, were evaluated

Three isomeric 4-[(n-bromophenyl)carbamoyl]butanoic acids (n =2,3 and 4) as DNA intercalator: Synthesis, physiochemical characterization, antimicrobial activity, antioxidant potential and in silico study

A series of three isomeric 4-[(n-bromophenyl)carbamoyl]butanoic acids (n=2,3 and 4) were synthesized and their structures confirmed by FTIR, NMR, MS, micro elemental analysis (CHN) and single crystal X-ray crystallography. Kinks are noted in the molecular structures of the n=2 and n=3 compounds, namely about the methylene-C–C(carbonyl) and N–C(phenyl) bonds; no such twist about the former bond is seen in the n=4 molecule. In the molecular packing, supramolecular tapes are carboxylic acid-O-H…O(carbonyl) and amide-N-H…O(amide) hydrogen bonds. The compounds were evaluated for interaction with salmon sperm DNA and found that they bind via an intercalative mode resulting in hypochromism and bathochromic shift as confirmed by the UV-visible spectroscopic and viscometric techniques. The results of antimicrobial activity performed against five bacterial and two fungal strains show that these compounds have < 50% inhibition. The DPPH antioxidant activity results revealed 78% maximum scavenging activity. An in silico study performed using the SwissADME webserver revealed the compounds obey the rules of drug-likeness and exhibit good potential for bioavailability

3-[(Z)-(4-Diethyl­amino-6-oxocyclo­hexa-2,4-dien-1-yl­idene)methyl­amino]benzoic acid

The title compound, C18H20N2O3, crystallizes as the keto tautomer, unlike the vast majority of similar structures that have been reported that contain the hydr­oxy tautomer. There are two strong hydrogen bonds in the crystal structure, both accepted by the same carbonyl group: one intra­molecular N—H⋯O and one inter­molecular O—H⋯O. As a result, the carbonyl C=O distance is long, at 1.310 (2) Å, which may suggest the mol­ecule has a significant zwitterionic character. The dihedral angle between the benzene ring planes is 15.05 (7)°. As a result of the intramolecular hydrogen bond, the bridging C—C=N—C group is almost coplanar with the benzene ring that has the diethylamino substituent [dihedral angle 2.35 (15)°]

3-[(Z)-(4-Diethylamino-6-oxocyclohexa-2,4-dien-1-ylidene)methylaminobenzoic acid

The title compound, Csb 18Hsb 20Nsb 2Osb 3, crystallizes as the keto tautomer, unlike the vast majority of similar structures that have been reported that contain the hydroxy tautomer. There are two strong hydrogen bonds in the crystal structure, both accepted by the same carbonyl group: one intra-molecular N—H⋅sO and one inter-molecular O—-H⋅sO. As a result, the carbonyl C=O distance is long, at 1.310(2)Å, which may suggest the molecule has a significant zwitterionic character. The dihedral angle between the benzene ring planes is 15.05(7)circ. As a result of the intramolecular hydrogen bond, the bridging C—-C=N—-C group is almost coplanar with the benzene ring that has the diethylamino substituent dihedral angle 2.35(15)circ

Effect of methylphenidate on visual responses in the superior colliculus in the anaesthetised rat: Role of cortical activation

The mechanism of action of psychostimulant drugs in the treatment of Attention Deficit Hyperactivity Disorder is still largely unknown, although recent evidence suggests one possibility is that the drugs affect the superior colliculus (SC). We have previously demonstrated that systemically administered d-amphetamine attenuates/abolishes visual responses to wholefield light flashes in the superficial layers of the SC in anaesthetised rats, and the present study sought to extend this work to methylphenidate (MPH). Anaesthetised rats were administered MPH at a range of doses (or saline) and subjected to monocular wholefield light flashes at two intensities, juxta-threshold and super-threshold. In contrast to d-amphetamine, systemic MPH produced an enhancement of visual activity at both intensities. Methylphenidate was also found to produce activation of the cortical EEG in anaesthetised rats. Furthermore, cortical activation induced by electrical stimulation of the pons was found to enhance visual responses in superficial layers of the SC, and when MPH was paired with pontine-induced cortical activation, the response-enhancing effects of MPH were substantially attenuated. Taken together, the results suggest that the enhancement of visual responses in the superficial layers of the SC by MPH in the anaesthetised rat is an artefact of the drug’s interaction with cortical arousal

Hydrolysis of tannic acid catalyzed by immobilized-stabilized derivatives of tannase from Lactobacillus plantarum

A recombinant tannase from Lactobacillus plantarum, overexpressed in Escherichia coli, was purified in a single step by metal chelate affinity chromatography on poorly activated nickel supports. It was possible to obtain 0.9 g of a pure enzyme by using only 20 mL of chromatographic support. The pure enzyme was immobilized and stabilized by multipoint covalent immobilization on highly activated glyoxyl agarose. Derivatives obtained by multipoint and multisubunit immobilization were 500- and 1000-fold more stable than both the soluble enzyme and the one-point-immobilized enzyme in experiments of thermal and cosolvent inactivation, respectively. In addition, up to 70 mg of pure enzyme was immobilized on 1 g of wet support. The hydrolysis of tannic acid was optimized by using the new immobilized tannase derivative. The optimal reaction conditions were 30% diglyme at pH 5.0 and 4 C. Under these conditions, it was possible to obtain 47.5 mM gallic acid from 5 mM tannic acid as substrate. The product was pure as proved by HPLC. On the other hand, the immobilized biocatalyst preserved >95% of its initial activity after 1 month of incubation under the optimal reaction conditionsThis work was supported by Grants AGL2008-01052, AGL-2009-07625, Consolider INGENIO 2010 CSD2007-00063 FUN-C-FOOD(CICYT),RM2008-00002 (INIA), and S-0505/AGR/000153 (CAM). J.A.C. is the recipient of a predoctoral fellowship from the I3P-CSIC Program and FPI-MEC, and G.F.-L. and L.B. are recipients of Ramon y Cajal postdoctoral contracts.Peer reviewe

NFC LearnTracker:Seamless support for learning with mobile and sensor technology

Lifelong learning activities are scattered along the day, in different locations and making use of multiple devices. Most of the times adults have to merge learning, work and everyday life making it difficult to have an account on how much time is devoted to learning activities and learning goals. Learning experiences are disrupted and mobile seamless learning technology provides new solutions to integrate daily life activities and learning in the same process. Hence, there is a need to provide tools that are smoothly integrated into adults’ daily life. This manuscript presents the NFC LearnTracker, a mobile tool proposing the user to immerse within his autobiography as a learner to identify successful physical learning environments, mark them with sensor tags, bind them to self-defined learning goals, keep track of the time invested on each goal with a natural interface, and monitor the learning analytics. This work implies a suitable tool for lifelong learners to bind scattered activities keeping them in a continuing learning flow. The NFC LearnTracker is released under open access licence with the aim to foster adaptation to further communities as well as to facilitate the extension to the increasing number of sensor and NFC tags existent in the market