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1.
Bioresour Technol ; 275: 368-374, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30605826

RESUMO

Crude supercritical lignin (SCL) extracted from hardwood (Quercus mongolica) treated via supercritical water (SCW) oxidation was subjected to sequential fractionation with four organic solvents; five lignin fractions (F1-F4 and FIN) were thus obtained. The molecular weight (MW) of the fractionated lignins gradually increased as fractionation proceeded. However, the content of methoxyl groups and phenolic hydroxyl groups tended to decrease with increasing molecular weight of the lignins. The functional groups of SCL and the fractionated lignins were very similar based on Fourier-transform infrared analysis. The syringyl/guaiacyl ratio (S/G ratio) of the fractionated lignins increased with an increase in the MW. The thermal stability decreased with decreasing MW of the fractionated lignins, and all fractions except for F1 had a maximum degradation temperature of around 360 °C. The glass transition temperature (Tg) of the fractions increased from 83 °C to 137 °C with increasing MW.


Assuntos
Biomassa , Fracionamento Químico/métodos , Lignina/isolamento & purificação , Água/química , Madeira/química , Lignina/química , Peso Molecular , Oxirredução , Solventes/química , Temperatura de Transição
2.
Biomed Res Int ; 2014: 105728, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24696841

RESUMO

This study investigated the cultivation of the marine microalga Chlorella sp. without supplying an inorganic carbon source, but instead with enriching the media with extracts of oyster shells pretreated by a high-pressure homogenization process. The pretreated oyster shells were extracted by a weak acid, acetic acid, that typically has harmful effects on cell growth and also poses environmental issues. The concentration of the residual dissolved carbon dioxide in the medium was sufficient to maintain cell growth at 32 ppm and pH 6.5 by only adding 5% (v/v) of oyster shell extracts. Under this condition, the maximum cell density observed was 2.74 g dry wt./L after 27 days of cultivation. The total lipid content was also measured as 18.1 (%, w/w), and this value was lower than the 23.6 (%, w/w) observed under nitrogen deficient conditions or autotrophic conditions. The fatty acid compositions of the lipids were also measured as 10.9% of C16:1 and 16.4% of C18:1 for the major fatty acids, which indicates that the biodiesel from this culture process should be a suitable biofuel. These results suggest that oyster shells, environmental waste from the food industry, can be used as a nutrient and carbon source with seawater, and this reused material should be important for easily scaling up the process for an outdoor culture system.


Assuntos
Exoesqueleto/química , Biocombustíveis/microbiologia , Biotecnologia/métodos , Chlorella/metabolismo , Misturas Complexas/farmacologia , Ostreidae/química , Animais , Dióxido de Carbono/farmacologia , Chlorella/efeitos dos fármacos , Chlorella/crescimento & desenvolvimento , Meios de Cultura/farmacologia , Concentração de Íons de Hidrogênio , Lipídeos/biossíntese , Nitrogênio/deficiência , Água do Mar
3.
Korean J Pediatr ; 54(1): 11-6, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21359055

RESUMO

PURPOSE: Enterovirus 71, one of the enteroviruses that are responsible for both hand-foot-and-mouth disease and herpangina, can cause neural injury. During periods of endemic spread of hand-foot-andmouth disease caused by enterovirus 71, CNS infections are also frequently diagnosed and may lead to increased complications from neural injury, as well as death. We present the results of our epidemiologic research on the clinical manifestations of children with CNS infections caused by enterovirus 71. METHODS: The study group consisted of 42 patients admitted for CNS infection by enterovirus 71 between April 2009 and October 2009 at the Department of Pediatrics of 5 major hospitals affiliated with the Catholic University of Korea. We retrospectively reviewed initial symptoms and laboratory findings on admission, the specimen from which enterovirus 71 was isolated, fever duration, admission period, treatment and progress, and complications. We compared aseptic meningitis patients with encephalitis patients. RESULTS: Of the 42 patients (23 men, 19 women), hand-foot-and-mouth disease was most prevalent (n=39), followed by herpangina (n=3), upon initial clinical diagnosis. Among the 42 patients, 15 (35.7%) were classified as severe, while 27 (64.3%) were classified as mild. Factors such as age, fever duration, presence of seizure, and use of intravenous immunoglobulin (IVIG) were statistically different between the 2 groups. CONCLUSION: Our results indicate that patients with severe infection caused by enterovirus 71 tended to be less than 3 years old, presented with at least 3 days of fever as well as seizure activity, and received IVIG treatment.

4.
Korean J Hematol ; 45(4): 236-41, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21253424

RESUMO

BACKGROUND: Combination treatment with all-trans-retinoic acid (ATRA) and anthracycline-based chemotherapy has led to major advances in the treatment of acute promyelocytic leukemia (APL). METHODS: In this study, we reviewed the outcome of pediatric APL patients treated using a modified AIDA protocol at our institution. RESULTS: Between May 1999 and December 2007, 23 patients were diagnosed with APL at the Department of Pediatrics, Saint Mary's Hospital, The Catholic University of Korea. Eleven patients were male (48%) (median age at diagnosis, 11 (range, 2-14) years). The treatment protocol consisted of remission induction (achieved by coadministration of ATRA and idarubicin), 3 courses of consolidation treatment, and 2 years of maintenance treatment during which ATRA was also administered. Three patients died early during remission induction due to CNS hemorrhage. The remaining 20 patients achieved complete remission (CR), with an overall CR rate of 87%. Two patients relapsed and died, and another patient died of pneumonia unrelated to APL. Four patients (17%) were diagnosed with ATRA syndrome, and all patients showed resolution of symptoms. The event-free survival (EFS) and overall survival (OS) of the cohort were 78.3±8.6% and 76.3±9.5%, respectively. Initial WBC count at diagnosis was the only significant prognostic factor for the rate of CR (P=0.039) and OS (P=0.039). CONCLUSION: A modified AIDA protocol for the treatment of childhood APL leads to improved EFS and OS, with limited ATRA syndrome-associated toxicity. Active monitoring and treatment of patients with high initial WBC counts may help in reducing mortality.

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