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Studies in Surface Science and Catalysis

A medical infusion pump (10) including an improved electric motor assembly (256). The medical infusion pump (10) includes a pumping mechanism (250) and a pump chamber (132) in an operative position with respect to the pumping mechanism (250), the pumping mechanism (250), manipulating the pump chamber (132) to pump liquid through the pump chamber. An electric motor (256) having a rotatable drive shaft (316) is operably linked to the pump driving mechanism (250), and the pump driving mechanism (250) pumps a select amount of liquid through the pump chamber (132) on each rotation of the electric motor drive shaft (316). The improved electric motor assembly (256) includes a motor having a portion of a drive shaft (388) extending therefrom. A magnet (392) is attached to the extending portion of the drive shaft for rotation with the drive shaft. A flux gatherer (396) is spaced from and magnetically coupled to the magnet (392) for biasing the poles of the magnet in a select orientation relative to the flux gatherer (396) so as to stop the pump driving mechanism (250) in a select position. A magnetic position detector (400) is spaced from and magnetically coupled to the magnet (392) for emitting an electrical signal each rotation of the drive shaft (388).

Ambulatory infusion pump

Sustainable metal-based catalysts for the synthesis of cyclic carbonates containing five-membered rings

Sustained mitogen-activated protein kinase (MAPK) and cytoplasmic phospholipase A2 activation by macrophage migration inhibitory factor (MIF). Regulatory role in cell proliferation and glucocorticoid action.

As the chemistry of saccharides and related molecular species plays a significant role in the metabolic pathways of living organisms, detecting the presence and concentration of biologically important sugars in aqueous solution is necessary in a variety of medicinal and industrial contexts. The recognition of d-glucose is of particular interest, for example in the monitoring of diabetics. Recent research provides clear evidence that tight control of blood sugar levels in diabetics sharply reduces the risk of long term complications, which include blindness, kidney failure, heart attacks and even gangrene and amputation of the limbs. Current enzymatic detection methods of sugars offer specificity for only a few saccharides; additionally, enzyme based sensors are unstable in harsh conditions. Phenylboronic acid has been known for 120 years. However, it took until 1959 for the first quantitative evaluation of saccharide boronic acid interactions. Boronic acids react with 1,2 or 1,3 diols of saccharides to form five- or six-membered cyclic esters in non-aqueous or basic aqueous media. The stable boronic acid-based saccharide receptors offer the possibility of creating saccharide sensors ‘chemosensors’ which are selective and sensitive for any chosen saccharide.

Artificial Receptors as Chemosensors for Carbohydrates

It is known that thiazolo[3,2-a][1,8]naphthyridine derivatives (3a) exhibit good antibacterial activity. Accordingly, several analogues of 3a, viz. oxazolo- and imidazolo[3,2-a][1,8]naphthyridine derivatives 3b and 3c, were synthesized and evaluated for antibacterial activity in vitro and for inhibitory activity against DNA gyrase of Escherichia coli K-12 C600. Compound 3a exhibited antibacterial activity comparable to that of ofloxacin and enoxacin against Gram-positive and Gram-negative bacteria and displayed antibacterial activity superior to that of 3b and 3c. The antibacterial activities of 3b and 3c decreased in that order. DNA gyrase inhibitory activities of 3a-c in E. coli K-12 C600 paralleled their in vitro antibacterial activity. It was found that enhancement of the DNA gyrase inhibitory activity of 3a was dependent on a certain feature of the sulfur atom of the thiazole ring.

Synthesis and antibacterial activity of thiazolo-, oxazolo-, and imidazolo[3,2-a][1,8]naphthyridinecarboxylic acids.

Chromophric receptors for nucleosides were designed utilizing the boronic acid–diol interaction which effectively operates in aqueous solution. Receptors consist of a boronic acid moiety and a dimethylaminophenylazo moiety. The boronic acid moiety forms a covalently-bonded ester linkage with the 2,3-diol group in nucleosides in a reversible manner and the anionic charge generated on the boron atom is stabilized intramolecularly by the pyridinium cation. The azo moiety can overlap with the heteroaromatic ring moiety in nucleosides to stabilize the complex. The complexation constants could be conveniently determined by the absorption spectral change. Comparison of the complexation constants with those of 2-deoxyadenosine without 2-OH and 1,4-anhydroerythritol without the heteroaromatic ring established that the complex formation is primarily due to the boronic acid–diol (2,3-diol) interaction and secondarily facilitated by the hydrophobic and/or π–π stacking interactions.

Molecular Design of Boronic Acid-Based Dye Receptors for Nucleosides

A novel series of 8-(2-substituted morpholino)-9,1-[(N-methylimino) methano]-7-fluoro-5-oxo-5H-thiazolo[3,2-a]quinoline-4-carboxylic acids, designated 8a-j, with a unique tetracyclic structure were synthesized, and the in vitro and in vivo antibacterial activities against Gram-positive strains, including methicillin-resistant Staphylococcus aureus isolates (MRSA), and Gram-negative strains were evaluated. These morpholino derivatives, 8a-j, showed excellent in vitro antibacterial activities against Gram-positive bacteria. The substitutions at the C-2 position of the 8-morpholino moiety of compound 8 play an important role in the enhancement of in vivo antibacterial activity. The unsubstituted morpholino derivative 8a, the 2,6-dimethyl derivative 8c, and the 2-ethylmorpholino derivative 8d showed poor in vivo antibacterial activity, while 8b, 8f-h, and 8j exhibited good activities. The 2-(methoxymethyl)morpholino derivative, 8h, showed the most potent activity in vivo. The therapeutic effects of 8h on systemic infection against S. aureus IID 803 were over 10-fold more potent than that of ofloxacin. Compound 8h, which showed superior oral bioavailability, has a chiral center. The enantiomers of 8h were synthesized, and the in vitro and in vivo antibacterial activities were evaluated. Both enantiomers, (S)-8h and (R)-8h, and the racemic compound 8 exhibited similar activities in vitro and in vivo. Compounds 8b and 8f-h also showed good levels of antibacterial activity against MRSA strains. The morpholino derivatives with unique tetracyclic structures are characterized by strong antibacterial activities against MRSA strains.

Synthesis and antibacterial activity of thiazolopyrazine-incorporated tetracyclic quinolone antibacterials.

A series of 8-substituted-9,1-(epoxymethano)-7-fluoro-5-oxo-5H- thiazolo[3,2-a]quinoline-4-carboxylic acids having a novel tetracyclic structure was synthesized and tested for antibacterial activity. The nature of the heteroatom (N, O, or S) substituted at the 8-position had little influence on the antibacterial activity. Among the six pyrrolidinyl derivatives and the five piperazinyl derivatives, the 8-(3-hydroxy-1-pyrrolidinyl) derivative 6h and the hydrochloride of the 8-(4-methyl-1-piperazinyl) derivative 6l showed the most potent activity against both Gram-positive and Gram-negative bacteria. Against nalidixic acid resistant strains, isolated from Escherichia coli KC-14, compound 6h was less potent than 6l. Replacement of the piperazinyl nitrogen atom by a carbon atom, an oxygen atom, or a sulfur atom (corresponding to the piperidino, morpholino, or thiomorpholino group, respectively) enhanced the activity against Gram-positive bacteria, but reduced the activity against Gram-negative bacteria. Compound 6l also showed potent in vivo antibacterial activity against Gram-positive and Gram-negative bacteria, and did not cause convulsions in mice with the concomitant administration of fenbufen. Replacement of the carboxy group by a sulfonic acid group in 6l resulted in a complete loss of antibacterial activity.

Masahiro Taguchi

Papers

Synthesis and antibacterial activity of thiazolo-, oxazolo-, and imidazolo[3,2-a][1,8]naphthyridinecarboxylic acids.

Molecular Design of Boronic Acid-Based Dye Receptors for Nucleosides

Synthesis and antibacterial activity of thiazolopyrazine-incorporated tetracyclic quinolone antibacterials.

Synthesis and Antibacterial Activity of New Tetracyclic Quinolone Antibacterials

Synthesis of New DNA Gyrase Inhibitors: Application of the DMSO Oxidation to the Conversion of the Amine into the Imine