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1.
Beilstein J Org Chem ; 11: 2117-24, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26664632

RESUMO

The first stereoselective synthesis of lippidulcines A, B and C has been accomplished starting from (+)-hernandulcin, which has been prepared on a multigram scale. The previously assigned absolute configurations have been confirmed. The key steps of this synthesis are based on a modified version of the Kornblum-DeLaMare rearrangement, and on a highly regioselective and stereoselective ketone reduction with the MeCBS reagent. The taste evaluations indicate that none of these sesquiterpenes are sweet, instead the lippidulcine A is a cooling agent with a mint after taste.

2.
Ultrason Sonochem ; 68: 105177, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32498035

RESUMO

To meet the objectives of the Intergovernmental Panel on Climate Change nations are adopting policies to encourage consumers to purchase electric vehicles. Electrification of the automobile industry reduces greenhouse gases but active metals for the cathode-LiCoO2 and LiNiO2-are toxic and represent an environmental challenge at the end of their lifetime. LiFePO4 (LFP) is an attractive alternative that is non-toxic, thermally stable, and durable but with a moderate theoretical capacity and a low electrical conductivity. Commercial technologies to synthesize LFP are energy-intensive, produce waste that incurs cost, and involve multiple process steps. Here we synthesize LFP precursor with lignin and cellulose in a sonicated grinding chamber of a wet media mill. This approach represents a paradigm shift that introduces mechanochemistry as a motive force to react iron oxalate and lithium hydrogen phosphate at ambient temperature. Ultrasound-assisted wet media milling increases carbon dispersion and reduces the particle size simultaneously. The ultrasound is generated by a 20 kHz,500 W automatic tuning ultrasound probe. The maximum discharge rate of the LFP synthesized this way was achieved with cellulose as a carbon source, after 9 h milling, at 70% ultrasound amplitude. After 2.5 h of milling, the particle size remained constant but the crystal size continued to drop and reached 29 nm. Glucose created plate-like particles, and cellulose and lignin produced spindle-shaped particles. Long mill times and high ultrasound amplitude generate smoother particle surfaces and the powder densifies after a spray drying step.

3.
Respir Med ; 153: 52-59, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31163350

RESUMO

BACKGROUND: Cystic fibrosis affects 1/3200 Caucasians. This genetic disease disturbs the ion and water homeostasis across epithelia, thus rendering mucus more viscous and harder to expel. Conventional treatments rely on the clapping method coupled with postural drainage. Despite the effectiveness of these procedures, they are invasive and enervating. METHODS: Here we study a new mechano-acoustic treatment device to help patients expectorate excess mucus, the Frequencer™. We test both normal and pathological synthetic mucin solutions (1 % and 4 % by weight) in vitro. We varied the frequency applied (from 20 Hz to 60 Hz) as well as the amplitude (from 50 % to 100 % intensity). Moreover, we assessed the effect of NaCl on mucus rehydration. RESULTS: A frequency of 40 Hz coupled with a 0.5 gL-1NaCl solution provokes partial mucus rehydration, regardless of the amplitude selected, as the work of adhesion measurements evidenced. CONCLUSIONS: Mechanical solicitation is fundamental to help patients affected by cystic fibrosis expectorate mucus. With an operating frequency of 20 Hz to 65 Hz, the Frequencer™ provides a gentler therapy than traditional methods (conventional chest physiotherapy). The Frequencer™ proved to be effective in the homogenization of synthetic mucin solutions in vitro in 20 min and elicited improved effectiveness in a mucin-rich environment.


Assuntos
Acústica/instrumentação , Fibrose Cística/terapia , Drenagem Postural/instrumentação , Muco/química , Animais , Fibrose Cística/epidemiologia , Fibrose Cística/fisiopatologia , Humanos , Fenômenos Mecânicos , Muco/efeitos dos fármacos , Muco/fisiologia , Modalidades de Fisioterapia/normas , Modalidades de Fisioterapia/estatística & dados numéricos , Ondas de Rádio/efeitos adversos , Solução Salina/efeitos adversos , Solução Salina/uso terapêutico , Suínos , Substâncias Viscoelásticas/química
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