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1.
J Environ Manage ; 359: 120963, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38728980

RESUMO

An efficient recycling process is developed to recover valuable materials from overhaul slag and reduce its harm to the ecological environment. The high temperature sulfuric acid roasting - water leaching technology is innovatively proposed to prepare Li2CO3 from overhaul slag. Under roasting conditions, fluorine volatilizes into the flue gas with HF, lithium is transformed into NaLi(SO4), aluminum is firstly transformed into NaAl(SO4)2, and then decomposed into Al2O3, so as to selective extraction of lithium. Under the optimal roasting - leaching conditions, the leaching rate of lithium and aluminum are 95.6% and 0.9%, respectively. Then the processes of impurity removal, and settling lithium are carried out. The Li2CO3 with recovery rate of 72.6% and purity of 98.6% could be obtained under the best settling lithium conditions. Compared with the traditional process, this work has short flow, high controllability, remarkable technical, economic, and environmental benefits. This comprehensive recycling technology is suitable for overhaul slag, and has great practical application potential for the disposal of other hazardous wastes in electrolytic aluminum industry.


Assuntos
Carbonato de Lítio , Reciclagem , Ácidos Sulfúricos , Ácidos Sulfúricos/química , Reciclagem/métodos , Carbonato de Lítio/química , Alumínio/química , Lítio/química , Água/química
2.
Bull Exp Biol Med ; 170(4): 436-439, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33713221

RESUMO

The use of lithium drugs in clinical practice requires constant monitoring of lithium plasma concentration, because toxicity is sometimes observed at therapeutic concentrations of lithium. This is often associated with fluctuations of plasma concentration of lithium ions after intake of individual doses. Therefore, the use of a porous carrier providing a stable blood level of the drug is extremely promising and important for clinical practice. We studied activity of a new lithium drug (lithium complex) consisting of aluminum-silicon base and lithium citrate immobilized on its surface. Lithium carbonate served as the reference drug. It was shown that lithium carbonate and lithium complex exhibited no anxiolytic activity in the conflict model, but produced an antidepressant effect and improved exploratory behavior of animals.


Assuntos
Lítio/farmacologia , Silicones/química , Óxido de Alumínio/química , Óxido de Alumínio/farmacologia , Animais , Ansiolíticos/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Carbonato de Lítio/química , Carbonato de Lítio/farmacologia , Masculino , Camundongos
3.
Molecules ; 25(2)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963280

RESUMO

Considered to be the next generation of heat transfer fluids (HTFs), nanofluids have been receiving a growing interest over the past decade. Molten salt nanofluids have been shown to have great potential as an HTF for use in high temperature applications such as direct absorption solar collector (DAC) system. Very few studies using molten salt nanofluids as the HTF in a DAC receiver can be found in the open literature. This study aimed to develop a 3D computational fluid dynamics model of the receiver of a DAC using graphite-nanoparticle-dispersed Li2CO3-K2CO3 molten salt nanofluid to investigate the effects of design and operation parameters on receiver performance. Receiver total efficiency using Li2CO3-K2CO3 salt was compared with that using solar salt nanofluid. Spectral properties of the base fluid and nanoparticles were modeled as wavelength-dependent and the absorption of the solar radiation was modeled as a volumetric heat release in the flowing heat transfer fluid. Initial results show that the receiver efficiency increases with increasing solar concentration, decreasing nanoparticle volume fraction, and decreasing receiver length. It was also found that the Carnot efficiency increases with increasing receiver length and nanoparticle volume fraction, and decreasing solar concentration and inlet velocity. Comparative study shows that solar salt HTF could provide higher total efficiency. However, a higher operating temperature of Li2CO3-K2CO3 will allow for a greater amount of thermal energy storage for a smaller volume of liquid.


Assuntos
Carbonatos/química , Grafite/química , Carbonato de Lítio/química , Nanopartículas/química , Potássio/química , Energia Solar , Adsorção , Algoritmos , Hidrodinâmica , Modelos Teóricos , Fenômenos Físicos , Reprodutibilidade dos Testes , Soluções
4.
Int J Med Mushrooms ; 20(9): 901-907, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30317983

RESUMO

Pleurotus ostreatus is a white-rot mushroom that bioaccumulates metals in basidiocarps and vegetative mycelia. This fungus has been used in soil and water bioremediation of several heavy metals; however, there are few studies of lithium mycelial bioaccumulation for pharmacological use. The aim of this study was to evaluate lithium bioaccumulation in P. ostreatus mycelia grown in a liquid malt extract cultivation medium with Li2CO3 or LiCl. Each lithium source was added to the medium to obtain a concentration of 0, 5, 10, 15, 20, 25, 30, 40, 50, 100, or 200 mg · L-1 lithium. The highest bioaccumulation of lithium in mycelia was 1575.29 µg · g-1 upon treatment with 40 mg · L-1 Li2CO3. P. ostreatus mycelia produce biomass and bioaccumulate both lithium sources, but more lithium bioaccumulates when in the form of Li2CO3. This study provides a prospective for the development of biotechnological products with high aggregate values and alternative ways to deliver lithium and eventually other salts for pharmacological use.


Assuntos
Carbonato de Lítio/metabolismo , Lítio/metabolismo , Micélio/metabolismo , Pleurotus/metabolismo , Relação Dose-Resposta a Droga , Lítio/química , Carbonato de Lítio/química , Micélio/química , Pleurotus/química
5.
Biomed Mater ; 13(6): 065003, 2018 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-30089710

RESUMO

The immunomodulatory effects of lithium have been reported across a range of models and contexts. Lithium appears to have a positive effect on osteogenesis in vivo, while in vitro outcomes throughout the literature are varied. Tissue engineering approaches have rarely targeted local lithium delivery within a regenerative setting. We hypothesized that part of the positive effects of lithium in vivo may be due to an immunomodulatory effect manifesting in a local environment. To achieve a sustained lithium release from scaffold constructs, we blended lithium carbonate, a soluble salt of lithium, with the biomaterial polymer polycaprolactone (PCL). We printed constructs of PCL alone, and with 5% (5Li) and 10% (10Li) lithium carbonate. Mechanical testing revealed that mechanical properties were largely retained with lithium carbonate incorporation, and we measured a consistent release of the ion over a 7 day period. The efficacy of our construct system was then assessed using a primary mouse macrophage culture, and a differentiated osteoclast culture. We found that the lithium released from constructs had a great effect on macrophage polarization, resulting in pronounced upregulation of immunomodulatory (M2) genes, and a decrease in pro-inflammatory (M1) genes. This was reflected in cytokine expression, and illustrated through immunofluorescent staining. Osteoclast activity was greatly suppressed by the lithium incorporation, with a marked effect on gene expression and actin ring formation. Our work demonstrated an effective system for local lithium delivery, confirmed the pronounced effects that lithium has on macrophage and osteoclast response, and sets the stage for further innovations in ion release for targeted tissue engineering.


Assuntos
Lítio/química , Macrófagos/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Poliésteres/química , Impressão Tridimensional , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/farmacologia , Células da Medula Óssea/citologia , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Citocinas/metabolismo , Sistemas de Liberação de Medicamentos , Fêmur/patologia , Inflamação , Carbonato de Lítio/química , Macrófagos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/metabolismo , Osteoclastos/citologia , Osteogênese/efeitos dos fármacos , Estresse Mecânico , Tíbia/patologia
6.
Environ Toxicol Pharmacol ; 61: 79-86, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29852373

RESUMO

Lithium carbonate is an effective drug against bipolar disorders. Direct use of lithium carbonate has been reported to result in lithium toxication and pulmonary complications. With chitosan micro and nanoparticles gaining attention for their protein absorption, drug targeting and improved dissolution rate of sparingly water-soluble drugs, this work has focused on chitosan loaded Li as a possible alternative to Li alone for cellular uptake. Well standardized ionic gelation technique employed in this study resulted in Li loaded chitosan nanoparticles with hydrodynamic diameter below 300 nm and zeta potential of + 30 mV and oval morphology. Through various techniques electrostatic interaction as well as Claritin dependent endocytic pathway is suggested as facilitating 1.3 times increase in cell proliferation in lithium carbonate loaded chitosan nanoparticles treated PC12 cells. A controlled Li release to the extent of less than 50% in 48 h from the nanoparticle was observed. This observation has very high significance as it ensures that the lithium toxicity can be avoided. These results indicated that chitosan is a promising carrier for lithium carbonate and may improve its therapeutic efficacy and also overcome toxicity during its use in the treatment of neuropsychiatric disorders.


Assuntos
Quitosana/administração & dosagem , Portadores de Fármacos/administração & dosagem , Carbonato de Lítio/administração & dosagem , Nanopartículas/administração & dosagem , Animais , Transporte Biológico , Proliferação de Células/efeitos dos fármacos , Quitosana/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Carbonato de Lítio/química , Carbonato de Lítio/toxicidade , Nanopartículas/química , Células PC12 , Ratos
7.
Anal Bioanal Chem ; 409(13): 3483-3493, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28324127

RESUMO

Three reference materials, at relatively low, middle, and high concentrations, were developed for analysis of the mass fractions of electrolytes (K, Ca, Na, Mg, Cl, and Li) in human serum. The reference materials were prepared by adding high purity chloride salts to normal human serum. The concentration range of the three levels is within ±20% of normal human serum. It was shown that 14 units with duplicate analysis is enough to demonstrate the homogeneity of these candidate reference materials. The statistical results also showed no significant trends in both short-term stability test for 1 week at 40 °C and long-term stability test for 14 months. The certification methods of the six elements include isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS), inductively coupled plasma optical emission spectroscopy (ICP-OES), atomic absorption spectroscopy (AAS), ion chromatography (IC), and ion-selective electrode (ISE). The certification methods were validated by international comparisons among a number of national metrology institutes (NMIs). The combined relative standard uncertainties of the property values were estimated by considering the uncertainties of the analytical methods, homogeneity, and stability. The range of the expanded uncertainties of all the elements is from 2.2% to 3.9%. The certified reference materials (CRMs) are primarily intended for use in the calibration and validation of procedures in clinical analysis for the determination of electrolytes in human serum or plasma. Graphical Abstract Certified reference materials for K, Ca, Mg, Na, Cl and Li in human serum (GBW09124-09126).


Assuntos
Análise Química do Sangue/métodos , Eletrólitos/química , Soro/química , Compostos de Cálcio/química , Humanos , Carbonato de Lítio/química , Cloreto de Magnésio/química , Óxidos/química , Cloreto de Potássio/química , Radioisótopos
8.
Bauru; s.n; 2017. 145 p. tab, graf, ilus.
Tese em Português | LILACS, BBO - odontologia (Brasil) | ID: biblio-879731

RESUMO

Neste trabalho desenhou-se bases de desenvolvimento, caracterização e avaliação dos aspectos biológicos relacionados ao Sistema BoneLithium, idealizado a partir da associação de partículas de carbonato de lítio dispersas em matriz gel de carbopol®, com capacidade de atuar como um sistema liberador de fármacos. Metodologicamente este estudo se dividiu em quatro partes: Na primeira delas, o objetivo central foi o desenvolvimento e a caracterização do biomaterial através da manipulação farmacológica. Na segunda etapa, avaliou-se a reação tecidual em subcutâneo de ratos, na terceira a influência das partículas de lítio liberadas pelo Sistema BoneLithium no reparo ósseo através de modelos experimentais utilizando coelhos, e por ultimo, a capacidade de cicatrização de defeitos ósseos criados cirurgicamente em calvária de ratos, tratados com o biomaterial e diferentes opções de enxertos ósseos com o objetivo de comparar a eficiência do Sistema BoneLithium aos protocolos pré-existentes. Experimentalmente, avaliou-se a reação tecidual onde se utilizou 15 ratos machos divididos aleatatoriamente em 5 grupos onde implantouse no subcutâneo tubos de butterfly contendo o biomaterial por períodos de preservação recomendados pela norma ADA 10993 para teste de reação tecidual. Os resultados demonstram que o Sistema BoneLithium apresenta reação tecidual normal. Para a avaliação do comportamento biológico do Sistema BoneLithium foram utilizados coelhos brancos adultos da raça New Zealand nos quais defeitos ósseos bilaterais de 1 cm de diâmetro foram confeccionados cirurgicamente na calvária e foram Tratados com o Sistema Bone Lithium do (lado Direito) e somente o Gel de Carbopol (lado esquerdo)/Coágulo sanguíneo (controle). A Histomorfometria demonstrou comportamento favorável ao reparo ósseo e adicionalmente através de Microtomografia Computadorizada (CT SKYSCAN), foi possível constatar diferenças significativas considerando p> 0.05 (ANOVA, Tukey) para o processo de reparo ósseo. A avaliação da performance do Sistema BoneLithium utilizando ratos Wistar nos quais foram criados defeitos críticos no centro da calvária e tratados com diferentes modalidades de enxertos ósseos (controle, autógeno, osso de banco (Unioss®, Marília Brasil), Bio-Oss® e associações com o Sistema BoneLithium. A histomorfometria mostrou diferenças significativas considerando p> 0.05 (ANOVA, Tukey) para avaliação de tecido conjuntivo pré-osteogênico e tecido ósseo neoformado, e quando avaliado qualitativamente por tomografia computadorizada de feixe cônico (I cat Cone Beam FOV 0.05 Xoran Tecnology, LLC, EUA e E-vol, CDT, Brasil), observaram-se áreas de neoformação óssea compatíveis com hiperdensidade óssea em toda a extensão do defeito quando apuradas em analises de paridade em escala Hounsfield. Dessa forma, conclui-se que no contexto deste estudo é possível concluir que Sistema BoneLithium representa uma alternativa com potencial viabilidade clínica e necessita seguimento de aplicação em novas metodologias.(AU)


In this work, bases for the development, characterization and evaluation of the biological aspects related to the BoneLithium System were designed, based on the association of lithium carbonate particles dispersed in carbopol® gel matrix, capable of acting as a drug-releasing system. Methodologically this study was divided in four parts: In the first one, the central objective was the development and characterization of the biomaterial through the pharmacological manipulation. In the second step, the tissue reaction was evaluated in subcutaneous of rats, in the third the influence of the lithium particles released by BoneLithium System in the bone repair through experimental models using rabbits, and finally, the capacity of healing of bone defects created surgically in Calvaria of rats, treated with the biomaterial and different options of bone grafts with the objective to compare the efficiency of the BoneLithium System to the preexisting protocols. Experimentally, the tissue reaction was evaluated in which 15 male rats were randomly divided into 5 groups, where butterfly tubes containing the biomaterial were implanted in the subcutaneous tubes for preservation periods recommended by the ADA 10993 standard for biocompatibility test. The results demonstrate that the BoneLithium System is tissue reaction positive. To evaluate the biological behavior of the BoneLithium System, adult New Zealand white rabbits were used in which bilateral bone defects of 1 cm in diameter were surgically made on calvaria and treated with the Bone Lithium System (right side) and only Gel Of Carbopol (left side) / blood clot (control). Histomorphometry showed a favorable behavior to bone repair and, in addition, through Computerized Microtomography (CT SKYSCAN), it was possible to verify significant differences considering p> 0.05 (ANOVA, Tukey) for the bone repair process. The evaluation of the performance of the BoneLithium System using Wistar rats in which critical defects were created at the calvarial center and treated with different bone graft modalities (control, autogenous, bone bank (Unioss®, Marília Brazil), Bio-Oss® and associations (ANOVA, Tukey) for evaluation of pre osteogenic connective tissue and neoformed bone tissue, and when assessed qualitatively by cone beam computed tomography (I cat - Cone Beam - FOV 0.05 - Xoran Tecnology, LLC, USA and E-vol, CDT, Brazil), areas of bone neoformation compatible with bone hyperdensity throughout the extent of the defect were ascertained in Hounsfield scale parity analyzes, It is concluded that in the context of this study it is possible to conclude that the BoneLithium System represents an alternative with potential clinical feasibility And requires follow-up of application in new methodologies.(AU)


Assuntos
Animais , Masculino , Coelhos , Ratos , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Substitutos Ósseos/química , Substitutos Ósseos/uso terapêutico , Carbonato de Lítio/química , Carbonato de Lítio/uso terapêutico , Materiais Biocompatíveis/química , Materiais Biocompatíveis/uso terapêutico , Transplante Ósseo/métodos , Tomografia Computadorizada de Feixe Cônico , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo
9.
ACS Comb Sci ; 18(6): 343-8, 2016 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-27124559

RESUMO

High-quality single-phase epitaxial LiCoO2 thin films are synthesized on 0.5 wt % Nb-doped SrTiO3(001) substrates by nanoscale alternate deposition of Li2CO3 and CoO as Li and Co sources, respectively, using a combinatorial pulsed laser deposition (PLD) technique. The formation of LiCoO2 thin films from these two sources results from the sintering reaction between Li2CO3 and CoO, which is commonly used in a bulk ceramics process, but simultaneously takes place on the substrate during the deposition at a temperature of 550 °C. Electrochemical characterization reveals that the charge/discharge property of LiCoO2 thin films as a cathode is severely sensitive to the nominal Li:Co composition ratio. The best-quality film shows an excellent discharge capacity comparable with the characteristic capacity of LiCoO2.


Assuntos
Cobalto/química , Técnicas de Química Combinatória/métodos , Óxidos/química , Estrôncio/química , Titânio/química , Cerâmica/síntese química , Técnicas Eletroquímicas , Lasers , Carbonato de Lítio/química , Nanotecnologia
10.
Bull Exp Biol Med ; 159(4): 490-3, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26388569

RESUMO

The functional activity of macrophages in response to injection of nanosized lithium carbonate particles after initiation of hepatocarcinoma 29 in male CBA mice was evaluated by the production of NO, arginase activity, and absorption of zymosan granules. In intact animals, NO production by peritoneal macrophages increased by 4 times and arginase activity 3.1 times in response to a single injection of nanosized particles into the hip muscle. The level of NO production by macrophages remained high after 4 and 5 injections, while arginase activity returned to normal. The level of phagocytic peritoneal macrophages increased by 1.4 times after 5 injections of the particles. The level of NO production by macrophages gradually increased in animals with hepatocarcinoma developing in the hip muscle: by 1.6 times on day 3, 3.2 times on day 7, and by 2.6 times on day 13 in comparison with the corresponding parameters in intact animals. The increase of NO production by peritoneal macrophages after tumor process initiation was not paralleled by changes in arginase activity and absorption of zymosan granules. The results indicated that injection of nanosized lithium carbonate particles after inoculation of hepatocarcinoma 29 cells in the right hip muscle tissue was inessential for the function of peritoneal macrophages by the studied parameters.


Assuntos
Carcinoma Hepatocelular/imunologia , Fatores Imunológicos/farmacologia , Carbonato de Lítio/farmacologia , Neoplasias Hepáticas/imunologia , Macrófagos Peritoneais/fisiologia , Animais , Arginase/metabolismo , Carcinogênese/imunologia , Células HT29 , Humanos , Fatores Imunológicos/química , Carbonato de Lítio/química , Macrófagos Peritoneais/efeitos dos fármacos , Masculino , Camundongos Endogâmicos CBA , Nanopartículas/química , Transplante de Neoplasias , Óxido Nítrico/biossíntese , Tamanho da Partícula , Fagocitose
11.
J Magn Reson ; 254: 131-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25899290

RESUMO

Lithium, in the form of lithium carbonate, is one of the most common drugs for bipolar disorder. Lithium is also considered to have an effect on many other cellular processes hence it possesses additional therapeutic as well as side effects. In order to quantitatively characterize the binding mode of lithium, it is required to identify the interacting species and measure their distances from the metal center. Here we use magic-angle spinning (MAS) solid-state NMR to study the binding site of lithium in complex with glycine and water (LiGlyW). Such a compound is a good enzyme mimetic since lithium is four-coordinated to one water molecule and three carboxylic groups. Distance measurements to carbons are performed using a 2D transferred echo double resonance (TEDOR) MAS solid-state NMR experiment, and water binding is probed by heteronuclear high-resolution proton-lithium and proton-carbon correlation (wPMLG-HETCOR) experiments. Both HETCOR experiments separate the main complex from impurities and non-specifically bound lithium species, demonstrating the sensitivity of the method to probe the species in the binding site. Optimizations of the TEDOR pulse scheme in the case of a quadrupolar nucleus with a small quadrupole coupling constant show that it is most efficient when pulses are positioned on the spin-1/2 (carbon-13) nucleus. Since the intensity of the TEDOR signal is not normalized, careful data analysis that considers both intensity and dipolar oscillations has to be performed. Nevertheless we show that accurate distances can be extracted for both carbons of the bound glycine and that these distances are consistent with the X-ray data and with lithium in a tetrahedral environment. The lithium environment in the complex is very similar to the binding site in inositol monophosphatase, an enzyme associated with bipolar disorder and the putative target for lithium therapy. A 2D TEDOR experiment applied to the bacterial SuhB gene product of this enzyme was designed to probe direct correlations between lithium, the enzyme inhibitor, and the closest carboxyl carbons of the binding site. At this point, the chemical shift of the bound carboxyl groups in this 29 kDa enzyme could be determined.


Assuntos
Lítio/química , Espectroscopia de Ressonância Magnética/métodos , Algoritmos , Bactérias/enzimologia , Sítios de Ligação , Simulação por Computador , Glicina/química , Carbonato de Lítio/química , Monoéster Fosfórico Hidrolases/química , Prótons , Ondas de Rádio , Água/química , Difração de Raios X
12.
Radiat Prot Dosimetry ; 161(1-4): 116-22, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24381203

RESUMO

In spite of considerable progress in neutron dosimetry, there is no dosemeter that is capable of measuring neutron doses independently of the neutron spectrum with good accuracy. Carbon-doped aluminium oxide (Al2O3:C) is a sensitive material for ionising radiation (beta-ray, X ray and electron) and has been used for applications in personal and medical dosimetry as an optically stimulated luminescence (OSL) dosemeter. Al2O3:C has a low sensitivity to neutron radiation; this prevents its application to neutron fields, representing a disadvantage of Al2O3:C-OSL when compared with LiF, which is used as a thermoluminescent detector. Recently an improvement for neutron dosimetry (Passmore and Kirr. Neutron response characterisation of an OSL neutron dosemeter. Radiat. Prot. Dosim. 2011; 144: 155-60) uses Al2O3:C coated with (6)Li2CO3 (OSLN),which gives the high-sensitive response as known for Al2O3:C with the advantage of being also sensitive to thermal neutrons. In this article, the authors compare small-size detectors (droplets) of Al2O3:C (OSL) and of Al2O3:C+(6)Li2CO3 (OSLN) and discuss the advantages and drawbacks of both materials, regarding size vs. response.


Assuntos
Carbonato de Lítio/química , Nêutrons , Radiometria/instrumentação , Óxido de Alumínio/química , Partículas beta , Carbono/química , Elétrons , Fluoretos/química , Raios gama , Íons , Compostos de Lítio/química , Luminescência , Imagens de Fantasmas , Polímeros/química , Radiometria/métodos , Raios X
13.
Artigo em Inglês | MEDLINE | ID: mdl-25570393

RESUMO

Lithium medication is the gold standard of treatment in Bipolar Disorder patients, preventing and reducing mood swings and suicidality. However, despite its effectiveness, it is a potentially hazardous drug requiring regular monitoring of blood levels to ensure toxic levels are not reached. This paper describes the first steps towards developing a new portable device that can be used by Bipolar Disorder patients to facilitate the analysis of lithium blood levels at home. Solutions of lithium carbonate have been optically fingerprinted using a high-end spectrophotometer. Preliminary measurements indicate that while the visible to near infrared region of the absorption spectra fall heavily within the water band, measurements in the Ultraviolet region show a strong distinction between different lithium concentrations. The optical spectra of Lithium in the 220 nm to 230 nm region demonstrated the ability to differentiate between concentrations representing those found in patients.


Assuntos
Transtorno Bipolar/sangue , Carbonato de Lítio/análise , Lítio/sangue , Óptica e Fotônica/métodos , Óptica e Fotônica/estatística & dados numéricos , Absorção Fisico-Química , Calibragem , Humanos , Carbonato de Lítio/química , Água/química
14.
J Org Chem ; 78(23): 11680-90, 2013 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-24171666

RESUMO

A robust convergent synthesis of the prodrugs of HCV replicase inhibitors 1-5 is described. The central 5H-imidazo[4,5-d]pyridazine core was formed from acid-catalyzed cyclocondensation of an imidazole-4,5-dicarbaldehyde (20) and a α-hydrazino ester, generated in situ from the bis-BOC-protected precursors 25 and 33. The acidic conditions not only released the otherwise unstable α-hydrazino esters but also were the key to avoid facile decarboxylation to the parent drugs from the carboxylic ester prodrugs 1-5. The bis-BOC α-hydrazino esters 25 and 33 were prepared by addition of ester enolates (from 23 and 32) to di-tert-butyl azodicarboxylate via catalysis with mild inorganic bases, such as Li2CO3. A selective aerobic oxidation with catalytic 5% Pt-Bi/C in aqueous KOH was developed to provide the dicarbaldehyde 20 from the diol 27.


Assuntos
Aldeídos/farmacologia , Antivirais/farmacologia , Ésteres/química , Hepacivirus/efeitos dos fármacos , Imidazóis/farmacologia , Pró-Fármacos/farmacologia , Replicação Viral/efeitos dos fármacos , Aldeídos/síntese química , Aldeídos/química , Antivirais/síntese química , Antivirais/química , Bismuto/química , Carbono/química , Catálise , Relação Dose-Resposta a Droga , Hidróxidos/química , Imidazóis/síntese química , Imidazóis/química , Carbonato de Lítio/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oxirredução , Platina/química , Compostos de Potássio/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Relação Estrutura-Atividade
15.
Dalton Trans ; 42(6): 1983-6, 2013 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-23280484

RESUMO

The structures of three novel compounds prepared from the reaction of the lower-rim 1,3-diacid calix[4]arene (LH(2)) with lithium carbonate (1), t-butyl-lithium (2) and zinc acetate (3) are reported.


Assuntos
Calixarenos/química , Carbonato de Lítio/química , Compostos Organometálicos/química , Fenóis/química , Acetato de Zinco/química , Cristalografia por Raios X , Ligação de Hidrogênio , Conformação Molecular
16.
Dent Mater J ; 31(5): 724-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23037833

RESUMO

This study aimed to develop a dental investment for titanium casting. ZrO(2) and Al(2)O(3) were selected as refractory materials to prepare three investments (Codes: A-C) according to the quantity of Zr. Al(2)O(3) cement was used as a binder at a ratio of 15%, they were mixed with special mixing liquid. B1 was used as a control mixed with water. Fundamental examinations were statistically evaluated. A casting test was performed with investment B. Fluidities, setting times, and green strengths showed no remarkable differences; however, they were significantly different from those of B1. Expansion values for A, B, C, and B1 at 850°C were 1.03%±0.08%, 1.96%±0.17%, 4.35%±0.23%, and 1.50%±0.28%, respectively. Castings were covered by only small amounts of mold materials. The hardness test showed no significant differences between castings from B and the ones from commercial investments. The experimental special mixing liquid effectively reduced the water/powder ratio and improved the strength and thermal expansion.


Assuntos
Revestimento para Fundição Odontológica/química , Técnica de Fundição Odontológica , Materiais Dentários/química , Titânio/química , Óxido de Alumínio/química , Força Compressiva , Dureza , Temperatura Alta , Humanos , Carbonato de Lítio/química , Teste de Materiais , Pós , Reologia , Estresse Mecânico , Propriedades de Superfície , Termodinâmica , Fatores de Tempo , Água/química , Zircônio/química
17.
Pharm Dev Technol ; 17(3): 375-82, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21284541

RESUMO

Lithium carbonate, a drug with narrow therapeutic index, needs therapeutic drug monitoring and dose adjustment to maintain lithium level within the therapeutic window. Conventional formulations of lithium carbonate exhibit immediate drug release causing swing/fluctuations in the plasma concentration of lithium, consequently leading to unfavorable side-effects and make dose adjustment difficult. The push-pull osmotic pump has been developed for zero order delivery of lithium carbonate for a period of 24 h. The effect of various formulation variables on bilayer core tablet and its semi permeable coating along with orifice diameter have been investigated and optimized for desired drug release profile. Drug release was found to be inversely proportional to the membrane thickness but directly related to the amount of pore formers in the semipermeable membrane. Images from a scanning electron microscope confirmed the presence of pores in the semipermeable membrane which facilitated the required water penetration. No distortion or change in orifice shape was noticed prior to and after the dissolution study. Drug release from the developed formulation was found to be independent of pH, agitation intensity and agitation mode but depended on osmotic pressure of dissolution media.


Assuntos
Antimaníacos/administração & dosagem , Sistemas de Liberação de Medicamentos , Carbonato de Lítio/administração & dosagem , Antimaníacos/química , Química Farmacêutica/métodos , Preparações de Ação Retardada , Concentração de Íons de Hidrogênio , Carbonato de Lítio/química , Microscopia Eletrônica de Varredura , Pressão Osmótica , Permeabilidade , Solubilidade , Comprimidos , Fatores de Tempo , Água/química
18.
J Magn Reson ; 213(1): 192-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21958755

RESUMO

We present a new approach to nondestructive magic-angle spinning (MAS) nuclear magnetic resonance (NMR) for thin films. In this scheme, the sample put on the top of a rotor is spun using the conventional MAS system, and the NMR signals are detected with an additional coil. Stable spinning of disk-shaped samples with diameters of 7 mm and 12 mm at 14.2 and 7 kHz are feasible. We present 7Li MAS NMR experiments of a thin-film sample of LiCoO2 with a thickness of 200 nm. Taking advantage of the nondestructive feature of the experiment, we also demonstrate ex situ experiments, by tracing conformation change upon annealing for various durations. This approach opens the door for in situ MAS NMR of thin-film devices as well.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Eletrodos , Lítio/química , Carbonato de Lítio/química , Espectroscopia de Ressonância Magnética/instrumentação
19.
Drug Dev Ind Pharm ; 37(3): 281-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20923390

RESUMO

The objective of this work was the development and validation of atomic absorption spectrometric (AAS) methods for the determination of residual active pharmaceutical ingredients (API) in rinse samples for cleaning validation. AAS as an indirect method for the determination of API in rinse samples can be applied when it is in the form of salt with metal ions or when the metal ion is a part of the API's structure. The electrothermal AAS methods (aqueous and ethanol medium) for the determination of magnesium in esomeprazole magnesium and the flame AAS method for the determination of lithium in lithium carbonate in rinse samples were developed. Various combinations of solvents were tested and a combination of 1% aqueous or ethanol solution of nitric acid for esomeprazole magnesium and 0.1% aqueous solution of nitric acid for lithium carbonate were found to be the most suitable. The atomization conditions in the graphite furnace and in the flame were carefully studied to avoid losses of analyte and to achieve suitable sensitivity. The cleaning verification methods were validated with respect to accuracy, precision, linearity, limit of detection, and quantification. In all the cases, the limits of detection were at the microgram level. The methods were successfully applied for the determination of esomeprazole magnesium and lithium carbonate in rinse samples from cleaning procedures.


Assuntos
Contaminação de Equipamentos/prevenção & controle , Esomeprazol/análise , Carbonato de Lítio/análise , Preparações Farmacêuticas/análise , Espectrofotometria Atômica/métodos , Antiulcerosos/análise , Antiulcerosos/química , Antimaníacos/análise , Antimaníacos/química , Esomeprazol/química , Etanol/química , Modelos Lineares , Lítio/análise , Carbonato de Lítio/química , Magnésio/análise , Reprodutibilidade dos Testes , Água/química
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