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Silicon-stereogenic chiral organosilanes have found increasing applications in synthetic chemistry, medicinal chemistry, and materials science. In this context, various asymmetric catalytic methods have been established for the diverse synthesis of silicon-stereogenic silanes. In particular, asymmetric organocatalysis is emerging as an important and complementary synthetic tool for the enantioselective construction of silicon-stereocenters, along with the rapid development of chiral-metal catalyzed protocols. Its advent provides a powerful platform to achieve functionalized silicon-stereogenic organosilanes with structural diversity, and should lead to great development in chiral organosilicon chemistry. In this Tutorial Review, we highlight these latest achievements from two aspects: desymmetrizations of prochiral tetraorganosilanes and dynamic kinetic asymmetric transformations of racemic organosilanes by employing five organocatalytic activation modes. The advantages, limitations and synthetic value of each protocol, as well as the synthetic opportunities still open for further exploration, are also discussed.
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We report an H-bond donor controlled diastereoselective switchable intramolecular aza-Henry reaction of ketimines derived from α-ketoesters and 2-(2-nitroethyl)anilines, allowing facile access to chiral tetrahydroquinolines bearing an aza-quaternary carbon stereocenter, which are privileged scaffold for medicinal researches. While newly developed cinchona alkaloid derived phosphoramide-bearing quaternary ammonium salt C2 selectively give cis-adducts in up to 20:1 dr and 99% ee, the corresponding urea-bearing analogue C8 preferentially give trans-adducts in up to 20:1 dr and 99% ee.
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Cannabinoid receptor 1 (CB1) is a G protein-coupled receptor and a therapeutic target for metabolic disorders. Numerous CB1 antagonists have been developed, but their functional selectivities and bias towards G protein or ß-arrestin signaling have not been systemically characterized. In this study, we analyzed the binding affinities and downstream signaling of two series of pyrazole derivatives bearing 1-aminopiperidine (Series I) or 4-aminothiomorpholine 1,1-dioxide (Series II) moieties, as well as the well-known CB1 antagonists rimonabant and taranabant. Analyses of the results for the Series I and II derivatives showed that minor structure modifications to their functional groups and especially the incorporation of 1-aminopiperidine or 4-aminothiomorpholine 1,1-dioxide motifs can profoundly affect their bias toward G protein or ß-arrestin signaling, and that their binding affinity and functional activity can be disassociated. Docking and molecular dynamics simulations revealed that the binding modes of Series I and II antagonists differed primarily in that Series I antagonists formed an additional hydrogen bond with the receptor, whereas those in Series II formed a water bridge.
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Antagonistas de Receptores de Cannabinoides , Proteínas de Unión al GTP , Antagonistas de Receptores de Cannabinoides/farmacología , Antagonistas de Receptores de Cannabinoides/metabolismo , Rimonabant , beta-Arrestinas/metabolismo , Proteínas de Unión al GTP/metabolismo , Receptores de Cannabinoides/metabolismoRESUMEN
BACKGROUND: An important conceptual advance in health and the environment has been recognized that enzymes play a key role in the green processing industries. Of particular interest, chitosanase is beneficial for recycling the chitosan resource and producing chitosan oligosaccharides. Also, chitosan gene expression and molecular characterization will promote understanding of the biological function of bacterial chitosanase as well as explore chitosanase for utilizing chitosan resources. RESULTS: A chitosanase-producing bacterium TY24 was isolated and identified as Bacillus cereus. Moreover, the chitosanase gene was cloned and expressed in Escherichia coli. Sequence analysis reveals that the recombinant chitosanase (CHOE) belongs to the glycoside hydrolases 8 family. The purified CHOE has a molecular weight of about 48 kDa and the specific activity of 1150 U/mg. The optimal pH and temperature of CHOE were 5.5 and 65 °C, respectively. The enzyme was observed stable at the pH range of 4.5-7.5 and the temperature range of 30-65 °C. Especially, the half-life of CHOE at 65 °C was 161 min. Additionally, the activity of CHOE was remarkably enhanced in the presence of Mn2+, Cu2+, Mg2+ and K+, beside Ca2+ at 5 mM. Especially, the activity of CHOE was enhanced to more than 120% in the presence of 1% of various surfactants. CHOE exhibited the highest substrate specificity toward colloid chitosan. CONCLUSION: A bacterial chitosanase was cloned from B. cereus and successfully expressed in E. coli (BL21) DE3. The recombinant enzyme displayed good stability under acid pH and high-temperature conditions.
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Bacillus cereus , Quitosano , Bacillus cereus/genética , Bacillus cereus/metabolismo , Quitosano/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Glicósido Hidrolasas/química , Clonación Molecular , Concentración de Iones de HidrógenoRESUMEN
BACKGROUND: With the growing concern for the environment, there are trends that bio-utilization of keratinous waste by keratinases could ease the heavy burden of keratinous waste from the poultry processing and leather industry. Especially surfactant-stable keratinases are beneficial for the detergent industry. Therefore, the production of keratinase by Bacillus cereus YQ15 was improved; the characterization and use of keratinase in detergent were also studied. RESULTS: A novel alkaline keratinase-producing bacterium YQ15 was isolated from feather keratin-rich soil and was identified as Bacillus cereus. Based on the improvement of medium components and culture conditions, the maximum keratinase activity (925 U/mL) was obtained after 36 h of cultivation under conditions of 35 °C and 160 rpm. Moreover, it was observed that the optimal reacting temperature and pH of the keratinase are 60 °C and 10.0, respectively; the activity was severely inhibited by PMSF and EDTA. On the contrary, the keratinase showed remarkable stability in the existence of the various surfactants, including SDS, Tween 20, Tween 60, Tween 80, and Triton X-100. Especially, 5% of Tween 20 and Tween 60 increased the activity by 100% and 60%, respectively. Furtherly, the keratinase revealed high efficiency in removing blood stains. CONCLUSION: The excellent compatibility with commercial detergents and the high washing efficiency of removing blood stains suggested its suitability for potential application as a bio-detergent additive.
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Bacillus cereus , Detergentes , Animales , Bacillus cereus/metabolismo , Detergentes/química , Estabilidad de Enzimas , Plumas/metabolismo , Concentración de Iones de Hidrógeno , Queratinas/metabolismo , Péptido Hidrolasas/metabolismo , Polisorbatos , Tensoactivos , TemperaturaRESUMEN
The changes in the gel and rheological properties and water-holding capacity of PSE meat myofibrillar proteins with different amounts of sodium bicarbonate (SC, 0−0.6/100 g) were studied. Compared to the PSE meat myofibrillar proteins with 0/100 g SC, the texture properties and cooking yield significantly increased (p < 0.05) with increasing SC; meanwhile, adding SC caused the gel color to darken. All samples had similar curves with three phases, and the storage modulus (G') values significantly increased with the increasing SC. The thermal stability of the PSE meat myofibrillar proteins was enhanced, and the G' value at 80 °C increased with the increasing SC. Because water was bound more tightly to the protein matrix, the initial relaxation times of T21 and T22 shortened, the peak ratio of P21 significantly increased (p < 0.05), and the P22 significantly decreased (p < 0.05), which implied that the mobility of the water was reduced. Overall, SC could improve the thermal stability of the PSE meat myofibrillar proteins and increase the water-holding capacity and textural properties of the cooked PSE meat myofibrillar protein gels.
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Proteínas de la Carne , Bicarbonato de Sodio , Agua , Culinaria , Reología , GelesRESUMEN
In this study, we analyze element geochemistry of submarine basalt in situ, which is sampled in hydrothermal areas from ultraslow spreading Southwest Indian Ridge, including the fresh basalt rocks (B19-9, B15-13) and altered basalt (B5-2). And we can confirm that altered mineral in B5-2 is celadonite by microscope and Raman Spectrum. Furthermore, amygdaloidal celadonites are analyzed by electron microprobe (EPMA) and EDS-line scanning. The results show that K-contents decrease and Na-contents increase from the core to the edge in these altered minerals, indicating the transition from celadonite to saponite. Celadonite is an altered minerals, forming in low temperature (< 50 degrees C) and oxidizing condition, while saponite form in low water/rock and more reducing condition. As a result, the transition from celadonite to saponite suggests environment change from oxidizing to reducing condition. Using the result of EPMA as internal standard, we can analyze rare earth elements (REE) in altered mineral in situ. Most of result show positive Eu anomaly (Δ(Eu)), indicating hydrothermal fluid transform from oxidizing to reducing, and reducing fluid rework on the early altered minerals. Comparison with REE in matrix feldspar both in altered and unaltered zoning, we find that reducing fluid can leach REE from the matrix feldspar, leading to lower total REE concentrations and positive Eu anomaly. So leaching process play an important role in hydrothermal system.
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In the present study, content and occurrence of Au, Ag in three submarine hydrothermal sulfide samples from the ultra-slow-spreading Southwest Indian Ridge (SWIR) were studied by using inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of ICP-AES show that all of the samples have signs of Au-Ag enrichment. By SEM/EDS, we discovered a mass of gold-silver minerals in the samples. In S27-4, gold occurs as irregular-shaped native gold and electrum grains in sulfides or between crystal particles. However, we discovered lots of Au-independent silver minerals except parts of electrum in S35-22. EDS results of silver minerals indicate that silver minerals closely related with halogen element, inferring that silver minerals may be silver halides. Electrum in S35-22 can be absorbed at the surface or crystal edge of pyrite besides occurring in or between sulfides as S27-4, supposed to be related to surface defect in pyrite. Electrum is the only Au-Ag mineral discovered in S35-17. These electrum gains occur as inclusion gold, absorbed gold or fissure gold. In addition, there are different Au-Ag mole ratios of electrum in three samples, indicating distinct hydrothermal conditions. In the base of research before, we consider that AgCl2(-) is the dominant complex of silver in ore-forming fluid of S27-4, however, gold is transported as AuCl2(-) transforming to AuHS(0), indicating that hydrothermal fluids decreased from high-moderate to moderate-low temperature and conductive cooling played an important role in this process. Similar enrichment mechanism happened in S35-22, but silver halides discovered in S35-22 suggest a higher temperature and chloride in the early stage. However, The enrichment of electrums in black smoke sample (S35-17) relates to mixing of hydrothermal fluids and seawater.
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To study the impact of ultrasonic duration (0, 30, and 60 min) and sodium bicarbonate concentration (0% and 0.2%) on the gel properties of reduced-salt pork myofibrillar protein, the changes in cooking yield, colour, water retention, texture properties, and dynamic rheology were investigated. The findings revealed that added sodium bicarbonate significantly increased (P < 0.05) cooking yield, hardness, springiness, and strength of myofibrillar protein while reducing centrifugal loss. Furthermore, the incorporation of sodium bicarbonate led to a significant decrease in Lâ, aâ, bâ, and white values of cooked myofibrillar protein; these effects were further amplified with increasing ultrasonic duration (P < 0.05). Additionally, storage modulus (G') significantly increased for myofibrillar protein treated with ultrasonic-assisted sodium bicarbonate treatment resulting in a more compact gel structure post-cooking. In summary, the results demonstrated that ultrasonic-assisted sodium bicarbonate treatment could enhance the tightness of reduced-salt myofibrillar protein gel structure while improving the water retention and texture properties.
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Carne de Cerdo , Carne Roja , Animales , Porcinos , Bicarbonato de Sodio , Ultrasonido , Carne Roja/análisis , Cloruro de Sodio , Cloruro de Sodio Dietético , Reología , Agua/químicaRESUMEN
Tigernut has been recognized as a promising resource for edible oil and starch. However, the research on the quality characteristics of tigernut from different regions is lagging behind, which limits the application of tigernut in food industry. Tigernut tubers were obtained from six major growing regions in China, and the physicochemical properties of their main components, oil and starch, were characterized. Tigernut tubers from Baoshan contained the most oil (30.12%), which contained the most ß-carotene (130.4 µg/100 g oil) due to high average annual temperature. Gas chromatography analysis and fingerprint analysis results indicated that tigernut oil (TNO) consists of seven fatty acids, of which oleic acid is the major component. Changchun TNO contained the least total tocopherols (6.04 mg/100 g oil) due to low average annual temperature. Tigernut tubers from Chifeng (CF) contained the most starch (34.85%) due to the large diurnal temperature range. Xingtai starch contained the most amylose (28.4%). Shijiazhuang starch showed the highest crystallinity (19.5%). Anyang starch had the highest pasting temperature (76.0°C). CF starch demonstrated superior freeze-thaw stability (syneresis: 50%) due to low mean annual precipitation. The results could be further applied to support tigernut industries and relevant researchers that looks for geographical origin discrimination and improvements on tigernut quality, with unique physicochemical and technological properties.
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Cyperus , Almidón , Almidón/química , Cyperus/química , Aceites de Plantas/química , Verduras , ChinaRESUMEN
This study was to explore the internal reasons for the changes in oil absorption performance of tigernut starch (TS) by revealing the high-temperature induced variations of structural and functional properties of TS. The results showed that as the temperature increased from 80 °C to 140 °C, the degree of starch gelatinization increased, while the proportion of double helix structures, the total proportion of B1 and B2 chains, the relative crystallinity and the molecular weight decreased, accompanied by the fragmentation and swelling of TS granules. The oxidation of tigernut oil (TNO) led to a decrease in oil density and an increase in total polar component content. These phenomena could result in an increase of oil absorption capacity of TS and starch-lipid complex index. With further increase in temperature from 170 °C to 200 °C, the disruption of the crystalline structure and chain structure increased, resulting in the melting and disintegration of TS granules. This caused a decrease in the starch-oil contact area and capillary absorption of TNO by the TS granules. The results will contribute to revealing the effect of high-temperature induced changes in the structural and functional properties of TS on its oil absorption properties.
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The majority of colon lesions are <10 mm in size and are easily resected by endoscopists with appropriate basic training. Lesions ≥10 mm in size are difficult to remove technically and are associated with higher rates of incomplete resection. Currently, the main endoscopic approaches include endoscopic mucosal resection (EMR) for lesions without submucosal invasion, and endoscopic submucosal dissection (ESD) for relatively larger lesions involving the superficial submucosal layer. Both of these approaches have limitations, EMR cannot reliably ensure complete resection for larger tumors and recurrence is a key limitation. ESD reliably provides complete resection and an accurate pathological diagnosis but is associated with risk such as perforation or bleeding. In addition, both EMR and ESD may be ineffective in treating subepithelial lesions that extend beyond the submucosa. Endoscopic full-thickness resection (EFTR) is an emerging innovative endoscopic therapy which was developed to overcome the limitations of EMR and ESD. Advantages include enabling a transmural resection, complete resection of complex colorectal lesions involving the mucosa to the muscularis propria. Recent studies comparing EFTR with current resection techniques and radical surgery for relatively complicated and larger lesion have provided promising results. If the current trajectory of research and development is maintained, EFTR will likely to become a strong contender as an alternative standard of care for advanced colonic lesions. In the current study we aimed to address this need, and highlighted the areas of future research, while stressing the need for multinational collaboration provide the steppingstone(s) needed to bring EFTR to the mainstream.
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If the tigernut meal left after oil extraction is used as a material for starch resources instead of being wasted, the industrial value of tigernut would be improved. Thus, we investigated the effect of extrusion before oil extraction on the yield, structure and function of starches within tigernut meals (TMS). Compared with the yield of native starch, the yield of TMS-130-11 (barrel temperature: 130 °C; feed moisture: 11 %) was increased by 1.97 %, and that of TMS-140-11 (barrel temperature: 140 °C; feed moisture: 11 %) was decreased by 7.82 %. The starches cannot be obtained when the barrel temperature is above 140 °C with 11 % feed moisture. Extrusion slightly decreased the relative crystallinity and increased the ratio of B2-chains in amylopectin. These changes resulted in reductions in peak viscosity while improving the elastic properties of the starch gel. These results will provide useful information regarding the use of starch isolated from tigernut meal.
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Amilopectina , Almidón , Amilopectina/química , Amilosa , Comidas , Almidón/química , Temperatura , ViscosidadRESUMEN
A highly enantio- and regio-selective Markovnikov hydromonofluoro(methyl)alkylation of 1,3-dienes was developed using redox-neutral nickel catalysis. It provided a facile strategy to construct diverse monofluoromethyl- or monofluoroalkyl-containing chiral allylic molecules. Notably, this represents the first catalytic asymmetric Markovnikov hydrofluoroalkylation of olefins. The practicability of this methodology is further highlighted by its broad substrate scope, mild base-free conditions, excellent enantio- and regio-selectivity, and diversified product elaborations to access useful fluorinated building blocks.
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BACKGROUND: Acute pancreatitis (AP) is an inflammatory disease in which the regulatory pathway is complex and not well understood. Soluble suppression of tumorigenicity 2 (sST2) protein receptor functions as a decoy receptor for interleukin (IL)-33 to prevent IL-33/suppression of tumorigenicity 2L (ST2L)-pathway-mediated T helper (Th)2 immune responses. AIM: To investigate the role of sST2 in AP. METHODS: We assessed the association between sST2 and severity of AP in 123 patients enrolled in this study. The serum levels of sST2, C-reactive protein (CRP) and Th1- and Th2-related cytokines, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-2, IL-4, IL-5 and IL-13, were measured by highly sensitive ELISA, and the severity of AP in patients was evaluated by the 2012 Atlanta Classification Criteria. RESULTS: Serum sST2 levels were significantly increased in AP patients, and further, these levels were significantly elevated in severe AP (SAP) patients compared to moderately severe AP (MSAP) and mild AP (MAP) patients. Logistic regression showed sST2 was a predictor of SAP [odds ratio (OR): 1.003 (1.001-1.006), P = 0.000]. sST2 cutoff point was 1190 pg/mL, and sST2 above this cutoff was associated with SAP. sST2 was also a predictor of any organ failure and mortality during AP [OR: 1.006 (1.003-1.009), P = 0.000, OR: 1.002 (1.001-1.004), P = 0.012, respectively]. Additionally, the Th1-related cytokines IFN-γ and TNF-α in the SAP group were higher and the Th2-related cytokine IL-4 in the SAP group was significantly lower than those in MSAP and MAP groups. CONCLUSION: sST2 may be used as a novel inflammatory marker in predicting AP severity and may regulate the function and differentiation of IL-33/ST2-mediated Th1 and Th2 Lymphocytes in AP homeostasis.
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Pancreatitis , Enfermedad Aguda , Biomarcadores , Citocinas , Humanos , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-13 , Pancreatitis/diagnóstico , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: Acute lung injury (ALI) is a common and life-threatening complication of severe acute pancreatitis (SAP). There are currently limited effective treatment options for SAP and associated ALI. Calycosin (Cal), a bioactive constituent extracted from the medicinal herb Radix Astragali exhibits potent anti-inflammatory properties, but its effect on SAP and associated ALI has yet to be determined. AIM: To identify the roles of Cal in SAP-ALI and the underlying mechanism. METHODS: SAP was induced via two intraperitoneal injections of L-arg (4 g/kg) and Cal (25 or 50 mg/kg) were injected 1 h prior to the first L-arg challenge. Mice were sacrificed 72 h after the induction of SAP and associated ALI was examined histologically and biochemically. An in vitro model of lipopolysaccharide (LPS)-induced ALI was established using A549 cells. Immunofluorescence analysis and western blot were evaluated in cells. Molecular docking analyses were conducted to examine the interaction of Cal with HMGB1. RESULTS: Cal treatment substantially reduced the serum amylase levels and alleviated histopathological injury associated with SAP and ALI. Neutrophil infiltration and lung tissue levels of neutrophil mediator myeloperoxidase were reduced in line with protective effects of Cal against ALI in SAP. Cal treatment also attenuated the serum levels and mRNA expression of pro-inflammatory cytokines tumor necrosis factor-α, interleukin-6, IL-1ß, HMGB1 and chemokine (CXC motif) ligand 1 in lung tissue. Immunofluorescence and western blot analyses showed that Cal treatment markedly suppressed the expression of HMGB1 and phosphorylated nuclear factor-kappa B (NF-κB) p65 in lung tissues and an in vitro model of LPS-induced ALI in A549 cells suggesting a role for HGMB1 in the pathogenesis of ALI. Furthermore, molecular docking analysis provided evidence for the direct interaction of Cal with HGMB1. CONCLUSION: Cal protects mice against L-arg-induced SAP and associated ALI by attenuating local and systemic neutrophil infiltration and inflammatory response via inhibition of HGMB1 and the NF-κB signaling pathway.
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Lesión Pulmonar Aguda , Proteína HMGB1 , Pancreatitis , Enfermedad Aguda , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/tratamiento farmacológico , Animales , Inflamación/tratamiento farmacológico , Isoflavonas , Lipopolisacáridos/toxicidad , Pulmón , Ratones , Simulación del Acoplamiento Molecular , FN-kappa B , Pancreatitis/inducido químicamente , Pancreatitis/complicaciones , Pancreatitis/tratamiento farmacológicoRESUMEN
The A-type Aurora kinase is upregulated in many human cancers, and it stabilizes MYC-family oncoproteins, which have long been considered an undruggable target. Here, we describe the design and synthesis of a series of pyrimidine-based derivatives able to inhibit Aurora A kinase activity and reduce levels of cMYC and MYCN. Through structure-based drug design of a small molecule that induces the DFG-out conformation of Aurora A kinase, lead compound 13 was identified, which potently (IC50 < 200 nM) inhibited the proliferation of high-MYC expressing small-cell lung cancer (SCLC) cell lines. Pharmacokinetic optimization of 13 by prodrug strategies resulted in orally bioavailable 25, which demonstrated an 8-fold higher oral AUC (F = 62.3%). Pharmacodynamic studies of 25 showed it to effectively reduce cMYC protein levels, leading to >80% tumor regression of NCI-H446 SCLC xenograft tumors in mice. These results support the potential of 25 for the treatment of MYC-amplified cancers including SCLC.
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Aurora Quinasa A/antagonistas & inhibidores , Diseño de Fármacos , Inhibidores de Proteínas Quinasas/síntesis química , Proteínas Proto-Oncogénicas c-myc/metabolismo , Pirimidinas/química , Animales , Aurora Quinasa A/metabolismo , Aurora Quinasa B/antagonistas & inhibidores , Aurora Quinasa B/metabolismo , Sitios de Unión , Proliferación Celular/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Ratones , Ratones Endogámicos ICR , Simulación del Acoplamiento Molecular , Inhibidores de Proteínas Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirimidinas/metabolismo , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Relación Estructura-Actividad , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Listeria monocytogenes (LM) is a food-borne pathogen inducing listeriosis, an illness characterized by encephalitis, septicaemia, and meningitis. Listeriolysin O (LLO) is absolutely required for virulence by L. monocytogenes, and is found only in virulent strains of the species. One of the best ways to detect and confirm the pathogen is detection of one of the virulence factors, LLO, produced by the microorganism. This paper focused on the electrical method used to detect the LLO toxin gene in food products and organism without labeling the target DNA. The electrochemical sensor was obtained by immobilizing single-stranded oligonucleotides onto the gold electrode with the mercaptan activated by N-hydroxysulfosuccinimide (NHS) and N-(3-dimethylamion)propyl-N'-ethyl carbodiimidehydrochloride (EDC). The hy-bridization reaction that occurred on the electrode surface was evidenced by Cyclic Voltammetry (CV) analysis using [Co(phen)3](ClO4)3 as an indicator. The covalently immobilized single-stranded DNA could selectively hybridize to its complementary DNA in solution to form double-stranded DNA on the gold surface. A significant increase of the peak cur-rent of Cyclic Voltammetry (CV) upon hybridization of immobilized ssDNA with PCR amplification products in the solu-tion was observed. This peak current change was used to monitor the amount of PCR amplification products. Factors deter-mining the sensitivity of the electrochemical assay, such as DNA target concentration and hybridization conditions, were investigated. The coupling of DNA to the electrochemical sensors has the potential of the quantitative evaluation of gene.
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Toxinas Bacterianas/análisis , Técnicas Electroquímicas/métodos , Proteínas de Choque Térmico/análisis , Proteínas Hemolisinas/análisis , Toxinas Bacterianas/genética , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Carbodiimidas/química , Cobalto/química , ADN Bacteriano/química , ADN Bacteriano/genética , ADN de Cadena Simple/química , ADN de Cadena Simple/genética , Técnicas Electroquímicas/instrumentación , Electrodos , Oro/química , Proteínas de Choque Térmico/genética , Proteínas Hemolisinas/genética , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/metabolismo , Listeriosis/diagnóstico , Listeriosis/microbiología , Compuestos Organometálicos/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Succinimidas/química , Compuestos de Sulfhidrilo/químicaRESUMEN
The present paper describes the use of optical waveguide lightmode spectroscopy (OWLS) for study of the binding interaction of the vascular endothelial growth factor (VGEF) with VEGF receptor 2 (VEGFR2). VEGF were immobilized in the surface of an 3-amino 3-propyltriethoxy silane (APTES) modified sensor chip. The solutions with different concentration of VEGFR2 were injected to the system to investigate the kinetic character with OWLS on the solid and liquid interface. The receptor binding and dissociation on the interface, quantified by association and dissociation rate coefficients ka and kd, were determined by the OWLS experiments. The k(a) and k(d) is 6.86 x 10(5) L x mol(-1) x s(-1) and 1.15 x 10(-3) s(-1), respectively. The results show that OWLS method could meet the requirement of kinetic determination of ligand--receptor interaction in applications for related fundamental research and pharmaceutical development.
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Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Cinética , Ligandos , Unión Proteica , Análisis EspectralRESUMEN
OBJECTIVE: To evaluate the value of the Centerpiece plate in the cervical single open-door laminoplasty and compared its advantages with conventional suture fixation methods. METHODS: From December 2009 to August 2011,32 patients with cervical spondylotic myelopathy were treated with operation. Of them, 15 cases underwent cervical single open-door laminoplasty and Centerpiece plate fixation (group A),there were 8 males and 7 females,aged from 51 to 65 years old with an average of 60.5 years and ranged in course of disease from 2 to 15 months; 17 cases underwent cervical single open-door laminoplasty and silk suture fixation (group B), there were 9 males and 8 females, aged from 49 to 66 years old with an average of 61.5 years and ranged in course of disease from 1 to 14 months. All the patients with unsteady gait symptom before operation and cervical MR imaging showed spinal cord compression and denaturation. According to standard of Japanese Orthopaedics Association (JOA) to evaluate the spinal nervers function before operation and at 6 months after operation;according to CT scan to determine the sagittal diameter (AP) of upper vertebral canal and cervical activity (ROM). RESULTS: All the patients were followed up from 8 to 20 months with an average of 13 months. All the incisions healed well and no complications such as internal fixation loosening and breakage,spinal cord injury, reclose-door were found. Postoperative symptoms relieved obviously and MRI and CT showed vertebral canal volume expanded significantly. Operative time and blood loss in group A were respectively (155.0+/-12.3) min, (407.0+/-11.8) ml and in group B were respectively (148.0+/-14.4) min, (398.0+/-15.4) ml. There was no significantly differenc, between two groups (P>0.05). JOA score in group A improved from preoperative 9.1+/-2.6 to postoperative 15.5+/-1.8 and in group B improved from preoperative 9.3 +/- 2.1 to postoperative 13.1 +/- 2.5 (P<0.05). CT sagittal diameter (AP) in group A increased from preoperative (10.7+/-2.4) mm to postoperative (17.6+/-3.2) mm and in group B increased from preoperative (11.6+/-1.7) mm to postoperative (15.9+/-2.0) mm (P<0.05). Cervical activity (ROM) in group A be- fore and after operation were respectively (51.0+/-2.6) degrees, (45.0+/-3.5) degrees and in group B were respectively (52.0+/-1.8) and (42.0+/-2.4). There was no significantly difference before operation between two groups (P>0.05) and there was significantly difference after operation between two groups (P<0.05). CONCLUSION: Treatment of cervical spondylotic myelopathy with posterior single open-door laminoplasty and Centerpiece plate fixation can enlarge spinal canal volume,keep original cervical activity, improve postoperative JOA score. The method has obviously advantages compared with traditional suture fixation methods.