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1.
Chem Sci ; 13(14): 4058-4069, 2022 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-35441000

RESUMEN

Lithium-free anode dual-ion batteries have attracted extensive studies due to their simple configuration, reduced cost, high safety and enhanced energy density. For the first time, a novel Li-free DIB based on a carbon paper anode (Li-free CGDIB) is reported in this paper. Carbon paper anodes usually have limited application in DIBs due to their poor electrochemical performance. Herein, by using a lithium bis(fluorosulfonyl)imide (LiFSI)-containing electrolyte, the battery shows outstanding electrochemical performance with a capacity retention of 96% after 300 cycles at 2C with a stable 98% coulombic efficiency and 89% capacity retention after 500 cycles at 5C with a stable coulombic efficiency of 98.5%. Moreover, the electrochemical properties of the CGDIB were investigated with a variety of in situ characterization techniques, such as in situ EIS, XRD and online differential electrochemical mass spectrometry (OEMS). The multifunctional effect of the LiFSI additive on the electrochemical properties of the Li-free CGDIB was also systematically analyzed, including generating a LiF-rich interfacial film, prohibiting Li dendrite growth effectively and forming a defective structure of graphite layers. This design strategy and fundamental analysis show great potential and lay a theoretical foundation for facilitating the further development of DIBs with high energy density.

2.
Shanghai Kou Qiang Yi Xue ; 31(6): 581-587, 2022 Dec.
Artículo en Chino | MEDLINE | ID: mdl-36970792

RESUMEN

PURPOSE: To trace the fate of transplanted stem cells from human exfoliated deciduous teeth (SHED) in the repair of periodontal bone defects, Molday ION rhodamine B (MIRB) was used to label SHED and explore the mechanism of SHED in the repair of periodontal bone defects. METHODS: In vitro cultured SHED were labeled by MIRB. The labeling efficiency, cell survival, proliferation and osteogenic differentiation of MIRB-labelled SHED were detected. The labeled cells were transplanted into the rat model with periodontal bone defect. The survival, differentiation and improvement of host periodontal bone healing of MIRB labeled SHED in vivo were analyzed by immunohistochemistry and fluorescence co-staining, nuclear magnetic imaging dual-mode tracking and H-E staining. The data were statistically analyzed with SPSS 24.0 software package. RESULTS: MIRB labeled SHED did not affect its growth and osteogenic differentiation. The optimal labeling concentration was 25 µg/mL, the labeling efficiency of SHED reached 100%. The transplantation of MIRB labeled SHED in vivo can survive for more than 8 weeks. It was found that MIRB labeled SHED could differentiate into osteoblasts in vivo and significantly promote the repair of alveolar bone defects. CONCLUSIONS: MIRB labeled SHED can be traced in vivo, and the effect of labeled SHED on the repair of defective alveolar bone was observed.


Asunto(s)
Pulpa Dental , Osteogénesis , Humanos , Ratas , Animales , Proliferación Celular , Células Madre , Diferenciación Celular , Diente Primario , Células Cultivadas
3.
Hum Genomics ; 15(1): 63, 2021 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-34657628

RESUMEN

BACKGROUND: Mutations in the SLC29A3 gene, which encodes the nucleoside transporter hENT3, have been implicated in syndromic forms of histiocytosis including H syndrome, pigmented hypertrichosis with insulin-dependent diabetes, Faisalabad histiocytosis and Familial Rosai-Dorfman disease (RDD). Herein, we report five new patients from a single family who present with phenotypes that associate features of H syndrome and Familial Rosai-Dorfman disease. METHODS: We investigated the clinical, biochemical, histopathological and molecular findings in five Tunisian family members' diagnosed with Familial RDD and/or H syndrome. The solute carrier family 29 (nucleoside transporters), member 3 (SLC29A3) gene was screened for molecular diagnosis using direct Sanger sequencing. RESULTS: Genetic analysis of all affected individuals revealed a previously reported missense mutation c.1088 G > A [p.Arg363Gln] in exon 6 of the SLC29A3 gene. Four affected members presented with clinical features consistent with the classical H syndrome phenotype. While their cousin's features were in keeping with Familial Rosai-Dorfman disease diagnosis with a previously undescribed cutaneous RDD presenting as erythematous nodular plaques on the face. This report underlines the clinical variability of SLC29A3 disorders even with an identical mutation in the same family. CONCLUSION: We report a rare event of 5 Tunisian family members' found to be homozygous for SLC29A3 gene mutations but showing a different phenotype severity. Our study reveals that despite a single mutation, the clinical expression of the SLC29A3 disorders may be significantly heterogeneous suggesting a poor genotype-phenotype correlation for the disease.


Asunto(s)
Histiocitosis Sinusal , Histiocitosis , Contractura , Pérdida Auditiva Sensorineural , Histiocitosis/genética , Histiocitosis Sinusal/genética , Histiocitosis Sinusal/patología , Humanos , Mutación , Proteínas de Transporte de Nucleósidos/genética
4.
ACS Appl Mater Interfaces ; 11(20): 18504-18510, 2019 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-31033271

RESUMEN

Lithium (Li) metal is a favorable anode for most energy storage equipment, thanks to its higher theoretical specific capacity. However, nonuniform Li nucleation/growth results in large-sized and irregular dendrites generated from the Li anode, which causes rapid capacity fade and serious safety hazard, hindering its widespread practical applications. In this paper, with the aid of a lithium nitrate (LiNO3) additive in a carbonate-based electrolyte, the Li anode shows low hysteresis for in excess of 1000 h at a current density of 0.5 mA cm-2. At the same time, a Li-graphite dual-ion battery exhibits an outstanding cycling stability at 5C; after 1000 cycles, 81% of the capacity is retained. After calculation, the Li-graphite dual-ion battery shows a competitive specific energy density of 243 Wh kg-1 at a power density of 234 W kg-1. Moreover, the linear sweep voltammetry test was first performed to analyze the Li nucleation/growth mechanism and explain the effect of the LiNO3 additive. The superior electrochemical properties of the Li-graphite dual-ion battery are ascribed to the formation of smooth Li composed of Li nanoparticles and a steady solid electrolyte interface film.

5.
ACS Appl Mater Interfaces ; 11(13): 12570-12577, 2019 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-30855934

RESUMEN

Dual-ion battery complements lithium-ion batteries in terms of the use of inexpensive materials and ease to construct cells. To improve the safety and energy density of dual-ion battery, in this paper, a novel MnO-graphite dual-ion battery is reported for the first time. Microporous MnO materials are used as anode, which exhibits a low conversion potential and a low voltage hysteresis. The MnO-graphite dual-ion battery can deliver a capacity of 104 mAh g-1 at 0.5C and exhibits good rate performances and cycling stability (capacity retention >93% after 300 cycles). A mechanism is proposed to explain the irreversibility in capacity during the initial cycle by using operando X-ray diffraction in combination with online electrochemical mass spectrometry and electrochemical impedance spectroscopy.

6.
Dalton Trans ; 45(21): 8862-8, 2016 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-27151184

RESUMEN

We prepared in this work an anchoring porphyrin and a series of hat-porphyrins. The zinc atom of the hat-porphyrins can be coordinated axially with the pyridine moiety of the anchoring porphyrin which is anchored on the titania surface by a carboxyl group. The structures of the assemblies were confirmed using computational calculations, transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). Solar cell devices of the monomer anchoring porphyrin and its assemblies were fabricated and the photovoltaic performances were measured under standard AM 1.5 sunlight irradiance. We found that the assembly devices showed higher JSC and lower VOC than that of the monomer anchoring porphyrin device. However, the comprehensive influence of JSC and VOC led to an enhancement in the solar-to-electric power-conversion efficiency (PCE) of the assemblies. We also studied the variation of JSC and VOC using electronic absorption and emission spectroscopy, charge extraction measurements, transient photovoltage decay measurements and electrochemical impedance spectroscopy.

7.
Sci Rep ; 6: 21524, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26876154

RESUMEN

In cancer cells, the mammalian target of rapamycin complex 1 (mTORC1) that requires hormonal and nutrient signals for its activation, is constitutively activated. We found that overexpression of pyruvate kinase M2 (PKM2) activates mTORC1 signaling through phosphorylating mTORC1 inhibitor AKT1 substrate 1 (AKT1S1). An unbiased quantitative phosphoproteomic survey identified 974 PKM2 substrates, including serine202 and serine203 (S202/203) of AKT1S1, in the proteome of renal cell carcinoma (RCC). Phosphorylation of S202/203 of AKT1S1 by PKM2 released AKT1S1 from raptor and facilitated its binding to 14-3-3, resulted in hormonal- and nutrient-signals independent activation of mTORC1 signaling and led accelerated oncogenic growth and autophagy inhibition in cancer cells. Decreasing S202/203 phosphorylation by TEPP-46 treatment reversed these effects. In RCCs and breast cancers, PKM2 overexpression was correlated with elevated S202/203 phosphorylation, activated mTORC1 and inhibited autophagy. Our results provided the first phosphorylome of PKM2 and revealed a constitutive mTORC1 activating mechanism in cancer cells.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/biosíntesis , Proteínas Portadoras/genética , Proteínas de la Membrana/genética , Complejos Multiproteicos/genética , Neoplasias/genética , Serina-Treonina Quinasas TOR/genética , Hormonas Tiroideas/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Autofagia/genética , Proteínas Portadoras/biosíntesis , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina , Proteínas de la Membrana/biosíntesis , Complejos Multiproteicos/antagonistas & inhibidores , Neoplasias/patología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/genética , Transducción de Señal/genética , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Hormonas Tiroideas/biosíntesis , Proteínas de Unión a Hormona Tiroide
8.
Sci Rep ; 5: 13768, 2015 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-26347949

RESUMEN

Cellulosome is a kind of multienzyme complex that displays high activity, selectivity, and stability. Here, we report a novel, non-cellulolytic, cellulosome-like multienzyme complex that produced by the Cellulosimicrobium cellulans wild-type strain F16 isolated from soil microflora. This multienzyme complex, with excellent catalytic efficiency of kcat 13.2 s(-1) to remove the C-7 xylosyl group from 7-xylosyl-10-deacetylpaclitaxel (10-DAXP), has an outstanding tolerance against organic solvents and an excellent general stability, with the long half-life of 214 hours. This cellulosome-like multienzyme complex has a novel structure distinct from the well-documented ones. The key catalytic subunit responsible for the ß-xylosidase activity against 10-DAXP is identified to be a novel protein, indicating a new glycoside hydrolase (GH) family. The pioneering work described here offers a novel nanoscale biocatalyst for the production of biofuels and chemicals from renewable plant-based natural resources.


Asunto(s)
Celulosomas/metabolismo , Complejos Multienzimáticos/química , Complejos Multienzimáticos/metabolismo , Secuencia de Aminoácidos , Catálisis , Activación Enzimática , Estabilidad de Enzimas , Genoma Bacteriano , Genómica , Glicósidos/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Hidrólisis , Cinética , Datos de Secuencia Molecular , Complejos Multienzimáticos/genética , Complejos Multienzimáticos/aislamiento & purificación , Paclitaxel/análogos & derivados , Paclitaxel/metabolismo , Estructura Secundaria de Proteína , Subunidades de Proteína , Alineación de Secuencia , Relación Estructura-Actividad , Especificidad por Sustrato
9.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 29(1): 49-54, 2013 Jan.
Artículo en Chino | MEDLINE | ID: mdl-23600132

RESUMEN

OBJECTIVE: To study proteins correlated with the mechanical properties of engineered cartilage by screening significantly changed proteins during cartilage formation by comparative proteomic analysis. METHODS: Human chondrocyte, cultured and expanded, were seeded onto a polyglycolic acid/polylactic acid (PGA/PLA) scaffolds. After 4 weeks of culture in vitro, the constructs were divided into three groups. There were 6 specimens in each group. For the regular in vitro culture group (A), the constructs were kept in culture at the original condition for an additional 6 weeks. For in vivo groups, the constructs were implanted subcutaneously into nude mice for either 6 weeks (B) or 12 weeks (C). All specimens were harvested for gross observation, average wet weight and volume measurement, histology, immunohistochemistry and biomechanics to evaluate the results. Meanwhile, comparative proteomic analysis was performed for each group, and those proteins involved in extracellular matrix with at least 2 folds up-regulation were chosen for further exploration. The correlations between Young's modulus and the relative content of the selected proteins were analyzed by Pearson correlation coefficient. RESULTS: All these samples in the three groups eventually formed hyaline-like cartilage structure. Specimens in C and B groups were similar with adult articular cartilage in appearance, and had multiple mature lacuna in histology. However, those specimens in A group had loose texture with irregular hypertrophy lacuna. Specimens implanted for 12 weeks in vivo had better wet weight (372.5 +/- 35.4) mg and Young's modulus (8.68 +/- 2.65) MPa than those cultured in vivo for 6 weeks (346 +/- 34.5) mg, (3.25 +/- 1.24) MPa (P < 0.01). In group A, they were (184.4 +/- 12.28) mg and (0.7 +/- 0.23) MPa. This study had detected 44 proteins in ECM by comparative proteomic analysis, then chosing the greatest ratio of 6 up-regulation proteins compared between C and A groups. The correlation results indicated the content of Decorin, Chondroadherin and Fibromodulin were linear correlation with the mechanical properties of engineered cartilage (P < 0.05). CONCLUSIONS: Comparative proteomic analysis could provide large scale information of associated proteins, making it profit for advanced research on the relationship between extracellular matrix and mechanical properties of engineered cartilage by combination with tissue reconstruction techniques.


Asunto(s)
Cartílago/metabolismo , Condrocitos/citología , Condrocitos/metabolismo , Proteoma/metabolismo , Ingeniería de Tejidos/métodos , Animales , Cartílago/citología , Cartílago/fisiología , Células Cultivadas , Feto/citología , Humanos , Ratones Desnudos , Proteómica , Andamios del Tejido
10.
Phytochem Anal ; 24(2): 171-5, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22936596

RESUMEN

INTRODUCTION: Stilbene glycosides are the primary constituents of Rheum tanguticum Maxim. ex Balf., to which different bioactivities has been attributed, including: anti-HIV, anti-oxidant, anti-tumour, anti-malarial, and anti-allergy activity. However, effective methods for the isolation and purification of stilbene glycosides, such as trans-rhapontin, cis-rhapontin and trans-desoxyrhaponticin, from this herb are not currently available. OBJECTIVE: To develop an efficient method for the preparative isolation and purification of three stilbene glycosides from Rheum tanguticum Maxim. ex Balf. via high-speed counter-current chromatography (HSCCC). METHODS: A solvent system composed of chloroform:n-butanol:methanol:water (4:1:3:2, v/v/v/v) was developed for the separation. The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase. The flow rate was 1.8 mL/min. The apparatus was controlled at 800 rpm and 25 °C, and the effluent was monitored at 280 nm. Chemical constituents were analysed by high-performance liquid chromatography (HPLC), and their structures were identified by ¹H- and ¹³C-NMR. RESULTS: Under the optimised conditions, 25.5 mg trans-rhapontin, 16.0 mg cis-rhapontin and 20.5 mg trans-desoxyrhaponticin were separated from 80 mg crude sample; the isolates had purities of 99.6, 97.2 and 99.2%, respectively. CONCLUSION: A simple and efficient HSCCC method has been optimised for the preparative separation of stilbene glycosides from Rheum tanguticum Maxim. ex Balf.


Asunto(s)
Distribución en Contracorriente/métodos , Glicósidos/aislamiento & purificación , Plantas Medicinales/química , Rheum/química , Estilbenos/aislamiento & purificación , Glicósidos/química , Estructura Molecular , Raíces de Plantas/química , Reproducibilidad de los Resultados , Solventes/química , Estilbenos/química , Tibet
11.
Artículo en Chino | WPRIM (Pacífico Occidental) | ID: wpr-271243

RESUMEN

<p><b>OBJECTIVE</b>To study proteins correlated with the mechanical properties of engineered cartilage by screening significantly changed proteins during cartilage formation by comparative proteomic analysis.</p><p><b>METHODS</b>Human chondrocyte, cultured and expanded, were seeded onto a polyglycolic acid/polylactic acid (PGA/PLA) scaffolds. After 4 weeks of culture in vitro, the constructs were divided into three groups. There were 6 specimens in each group. For the regular in vitro culture group (A), the constructs were kept in culture at the original condition for an additional 6 weeks. For in vivo groups, the constructs were implanted subcutaneously into nude mice for either 6 weeks (B) or 12 weeks (C). All specimens were harvested for gross observation, average wet weight and volume measurement, histology, immunohistochemistry and biomechanics to evaluate the results. Meanwhile, comparative proteomic analysis was performed for each group, and those proteins involved in extracellular matrix with at least 2 folds up-regulation were chosen for further exploration. The correlations between Young's modulus and the relative content of the selected proteins were analyzed by Pearson correlation coefficient.</p><p><b>RESULTS</b>All these samples in the three groups eventually formed hyaline-like cartilage structure. Specimens in C and B groups were similar with adult articular cartilage in appearance, and had multiple mature lacuna in histology. However, those specimens in A group had loose texture with irregular hypertrophy lacuna. Specimens implanted for 12 weeks in vivo had better wet weight (372.5 +/- 35.4) mg and Young's modulus (8.68 +/- 2.65) MPa than those cultured in vivo for 6 weeks (346 +/- 34.5) mg, (3.25 +/- 1.24) MPa (P < 0.01). In group A, they were (184.4 +/- 12.28) mg and (0.7 +/- 0.23) MPa. This study had detected 44 proteins in ECM by comparative proteomic analysis, then chosing the greatest ratio of 6 up-regulation proteins compared between C and A groups. The correlation results indicated the content of Decorin, Chondroadherin and Fibromodulin were linear correlation with the mechanical properties of engineered cartilage (P < 0.05).</p><p><b>CONCLUSIONS</b>Comparative proteomic analysis could provide large scale information of associated proteins, making it profit for advanced research on the relationship between extracellular matrix and mechanical properties of engineered cartilage by combination with tissue reconstruction techniques.</p>


Asunto(s)
Animales , Humanos , Cartílago , Biología Celular , Metabolismo , Fisiología , Células Cultivadas , Condrocitos , Biología Celular , Metabolismo , Feto , Biología Celular , Ratones Desnudos , Proteoma , Metabolismo , Proteómica , Ingeniería de Tejidos , Métodos , Andamios del Tejido
12.
J Chromatogr A ; 1167(2): 178-83, 2007 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-17850806

RESUMEN

A novel technique for removal of three-dimensional background drift in comprehensive two-dimensional (2D) liquid chromatography coupled with diode array detection (LCxLC-DAD) data is proposed. The basic idea is to perform trilinear decomposition on the instrumental response data, which is based on the alternating trilinear decomposition (ATLD) algorithm. In model construction, the background drift is modeled as one component or factor as well as the analytes of interest, hence, the drift is explicitly included into the calibration. The method involves performing trilinear decomposition on the raw data, then extracting the background component and subtracting this background data from the raw data, leaving the analytes' signal on a flat baseline. Simultaneous evaluation of three-dimensional background drift and true signals may improve the quality of the data. This method is applied to the determination and removal of three-dimensional background drifts in simulated multidimensional data as well as experimental comprehensive two-dimensional liquid chromatographic data. It is shown that this technique yield a good removal of background drift, without the need to perform a blank chromatographic run, and required no prior knowledge about the sample composition.


Asunto(s)
Cromatografía Liquida/métodos , Modelos Teóricos , Algoritmos , Calibración , Simulación por Computador , Medicamentos Herbarios Chinos/análisis , Medicamentos Herbarios Chinos/química , Ligusticum , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta
13.
Artículo en Chino | MEDLINE | ID: mdl-16775410

RESUMEN

Photosynthetic electron transport and light energy allocation were studied in the alpine plants Anisodus tanguticus (Maxim.) Pascher and Rheum tanguticum Maxim. ex Balf on the Qinghai-Tibet Plateau by using gas exchange and chlorophyll fluorescence. The results indicated that apparent quantum yield (AQY) of leaves of A. tanguticus was marginally higher than that of R. tanguticum although it had a lower maximum net photosynthetic rate (Pmax). The net photosynthetic rate (P(n)) of A. tanguticus was higher than R. tanguticum within the range of middle photosynthetic photon flux density (PPFD). However, the P(n) in R. tanguticum increased concomitantly with PPFD and did not appear to show light saturation of P(n) even under 2000 micromol m(-2) s(-1) which is similar to full light in summer (Fig.1). Increasing the PPFD to 1200 micromol m(-2) s(-1) decreased the ratio of carboxylation rate to total photosynthetic electron flow rate (J(C)/J(F)) although increased the ratio of photorespiration (J(O)/J(F)) for both species. Both J(C)/J(F) and J(O)/J(F) stabilized with a PPFD of more than 1200 micromol m(-2) s(-1) (Fig.2). The changes in the ratios of Rubisco oxygenation to carboxylation (V(O)/V(C)) were similar to changes to J(O)/J(F) (Fig.3). The increase of thermal energy dissipation (D) in A. tanguticus was higher than R. tanguticum with increased PPFD (Fig.4). It can be concluded that the two species adopt different mechanisms to cope with increased solar radiation. Increasing the fractions of PSII thermal energy dissipation and electron transport through photorespiration were the main adaptations in A. tanguticus. Enhancement of photosynthetic capacity with increased PPFD to balance the higher light energy absorbed by leaves is considered the main adaptation for R. tanguticum.


Asunto(s)
Luz , Fotosíntesis/efectos de la radiación , Rheum/efectos de la radiación , Solanaceae/efectos de la radiación , Transporte de Electrón/fisiología , Transporte de Electrón/efectos de la radiación , Fotosíntesis/fisiología , Plantas Medicinales/fisiología , Plantas Medicinales/efectos de la radiación , Rheum/fisiología , Solanaceae/fisiología , Tibet
14.
J Pharm Biomed Anal ; 38(2): 216-24, 2005 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-15925211

RESUMEN

Immobilized liposome chromatography (ILC), the stationary phase of which has been regarded as a mimic biomembranes system was used to separate and analyze compounds interacting with liposome membrane in Danggui Buxue decoction, a combined prescription of traditional Chinese medicines (CPTCMs), and its compositions Radix Astragli and Radix Angelica Sinensis. More than 10 main peaks in the extract of Danggui Buxue decoction were resolved on the ILC column, suggesting that more than 10 components in the prescription have significant retention on ILC column. Ligustilide, astragaloside IV and formononetin, three main bioactive ingredients in Danggui Buxue decoction, were found to have relatively significant, while ferulic acid, another bioactive ingredient in the prescription, relatively weak retention on ILC column. Effects of the eluent pH and amount of immobilized phosphatidylcholine (PC) on separation of interactional compounds in the extract of Danggui Buxue decoction were also investigated. It was found that these two factors strongly affected the retention of some interactional compounds. In addition, the fractions partitioned with different solvents from water extract of this combined prescription were evaluated with this ILC column system.


Asunto(s)
Cromatografía/métodos , Medicamentos Herbarios Chinos/aislamiento & purificación , Liposomas/química , Cromatografía Líquida de Alta Presión/métodos , Ácidos Cumáricos/análisis , Medicamentos Herbarios Chinos/análisis , Medicamentos Herbarios Chinos/química , Concentración de Iones de Hidrógeno , Isoflavonas/análisis , Fosfatidilcolinas/química , Saponinas/análisis , Tecnología Farmacéutica/métodos , Triterpenos/análisis
15.
J Proteome Res ; 4(2): 613-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15822942

RESUMEN

A resurgence of interest in the human plasma proteome has occurred in recent years because it holds great promise of revolution in disease diagnosis and therapeutic monitoring. As one of the most powerful separation techniques, multidimensional liquid chromatography has attracted extensive attention, but most published works have focused on the fractionation of tryptic peptides. In this study, proteins from human plasma were prefractionated by online sequential strong cation exchange chromatography and reversed-phase chromatography. The resulting 30 samples were individually digested by trypsin, and analyzed by capillary reversed-phase liquid chromatography coupled with linear ion trap mass spectrometry. After meeting stringent criteria, a total of 1292 distinct proteins were successfully identified in our work, among which, some proteins known to be present in serum in <10 ng/mL were detected. Compared with other works in published literatures, this analysis offered a more full-scale list of the plasma proteome. Considering our strategy allows high throughput of protein identification in serum, the prefractionation of proteins before MS analysis is a simple and effective method to facilitate human plasma proteome research.


Asunto(s)
Proteínas Sanguíneas/química , Cromatografía Liquida/métodos , Espectrometría de Masas/métodos , Proteoma , Adulto , Femenino , Humanos
16.
Rapid Commun Mass Spectrom ; 18(18): 2169-76, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15378723

RESUMEN

Since protein phosphorylation is a dominant mechanism of information transfer in cells, there is a great need for methods capable of accurately elucidating sites of phosphorylation. In recent years mass spectrometry has become an increasingly viable alternative to more traditional methods of phosphorylation analysis. The present study used immobilized metal affinity chromatography (IMAC) coupled with a linear ion trap mass spectrometer to analyze phosphorylated proteins in mouse liver. A total of 26 peptide sequences defining 26 sites of phosphorylation were determined. Although this number of identified phosphoproteins is not large, the approach is still of interest because a series of conservative criteria were adopted in data analysis. We note that, although the binding of non-phosphorylated peptides to the IMAC column was apparent, the improvements in high-speed scanning and quality of MS/MS spectra provided by the linear ion trap contributed to the phosphoprotein identification. Further analysis demonstrated that MS/MS/MS analysis was necessary to exclude the false-positive matches resulting from the MS/MS experiments, especially for multiphosphorylated peptides. The use of the linear ion trap considerably enabled exploitation of nanoflow-HPLC/MS/MS, and in addition MS/MS/MS has great potential in phosphoproteome research of relatively complex samples.


Asunto(s)
Cromatografía de Afinidad/métodos , Hígado/metabolismo , Espectrometría de Masas/métodos , Fosfoproteínas/análisis , Proteoma/análisis , Análisis de Secuencia de Proteína/métodos , Secuencia de Aminoácidos , Animales , Sitios de Unión , Femenino , Técnicas In Vitro , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Fosfoproteínas/química , Fosforilación , Proteoma/química
17.
Se Pu ; 20(5): 436-8, 2002 Sep.
Artículo en Chino | MEDLINE | ID: mdl-16358696

RESUMEN

A cinchonine imprinted chiral monolithic column was prepared for the separation of the diastereomers of cinchonine and cinchonidine by in-situ molecular imprinting technique. This type of molecularly imprinted column can be prepared only by a single-step procedure. In order to improve the selectivity and efficiency, a new in-situ molecular imprinting polymerization system was introduced by adopting porogenic solvents of toluene and 1-dodecanol with relatively low polarity and appropriate ratios of polymerization mixture. Diastereomers of cinchonine and cinchonidine were fully separated both under isocratic and gradient elutions on the chiral monolithic column. The broad peak shown in isocratic elution could be improved in gradient elution. Effects of mobile phase composition, flow rate and temperature on retention and separation factor were investigated. Due to the large throughput pores in the chiral monolithic column, low backpressure was observed during the separation process and a separation factor of 3.18 was obtained at 1.0 mL/min. The increase of temperature could improve the separation factor and a maximum separation factor of 5.40 was obtained at 60 degrees C.

18.
Se Pu ; 20(2): 97-101, 2002 Mar.
Artículo en Chino | MEDLINE | ID: mdl-12541961

RESUMEN

Referring to traditional optimal methods, a method for the optimization of isocratic elution mobile phase composition in high performance liquid chromatography has been developed. In this method, the genetic algorithm based on line-crossover and plane-mutation is used. The principle of genetic algorithm and the process of optimization of mobile phase composition in reversed-phase ion-pair high performance liquid chromatography using genetic algorithm are introduced in details. With the concentrations of acetonitrile and ion-pair reagent sodium octane sulfonate chosen as the optimal parameters, the optimum was obtained by three times of optimization procedures. The mean relative error between the predicted and experimental values was 0.75% at the optimum and the optimization results were satisfactory.


Asunto(s)
Aminoácidos/aislamiento & purificación , Cromatografía Líquida de Alta Presión/métodos , Genética , Algoritmos , Mapeo Peptídico
19.
Se Pu ; 20(2): 137-9, 2002 Mar.
Artículo en Chino | MEDLINE | ID: mdl-12541970

RESUMEN

The best conditions for the reaction of meso-tetra(4-sulfophenyl)-porphyrin (TPPS4) with Mn2+, Ni2+, Zn2+ and Cu2+ have been investigated. A method for the fast determination of Ni2+, Mn2+, Zn2+ and Cu2+ has been developed: microwave derivatization at 750 W for 3 min, C18 column, acetonitrile-water(22.5:77.5, volume ratio) as mobile phase with tetraethylammonium bromide (TEABr) as ion-pair reagent and detection wavelength of 415 nm. The detection limits for Zn2+, Cu2+, Ni2+ and Mn2+ were 0.05 microgram/L, 0.01 microgram/L, 0.10 microgram/L and 0.40 microgram/L, respectively. This method has been applied to analyze the concentrations of these four metal ions in marketed tea.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Cobre/análisis , Níquel/análisis , Cromatografía Líquida de Alta Presión/instrumentación , Manganeso/análisis , Metaloporfirinas , Microondas , Té/química , Zinc/análisis
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