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1.
Molecules ; 27(22)2022 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-36431813

RESUMEN

This work was focused on the rust conversion of proanthocyanidins (PC) for goethite (α-FeOOH), akaganeite (ß-FeOOH) and lepidocrocite (γ-FeOOH), trying to show the potential of PC as an eco-friendly corrosion inhibitor and rust converter for archaeological steel conservation. The experiment used a rusted steel screw from Lingzhao Xuan of the Forbidden City in the Qing Dynasty and three kinds of pure iron oxyhydroxides as research samples. By means of micro-Raman, FTIR, XRD, XPS, SEM and EIS, PC had the ability to chemically react with iron oxyhydroxides in the rust, forming amorphous PC-FeOOH with a marked signal about 1384 cm-1 as phenolic-Fe in infrared properties. The original relatively stable iron oxides were not induced to phase transformation and still remained. The converted rust layer could be more stable in the corrosive medium and increased the corrosion potential more effectively. Both the rust layer resistance and the charge transfer resistance of the archaeological samples were improved by at least 3 times with 5.0 g/L of PC, which could reasonably stabilize the archaeological rust and hindered external corrosive penetration into the core. It was a mild protection material that showed satisfactory performance for archaeological steel cultural heritage and has a good application prospect.


Asunto(s)
Cáusticos , Proantocianidinas , Acero/química , Hierro/química
2.
Nature ; 466(7305): 503-7, 2010 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-20622853

RESUMEN

X-linked mental retardation (XLMR) is a complex human disease that causes intellectual disability. Causal mutations have been found in approximately 90 X-linked genes; however, molecular and biological functions of many of these genetically defined XLMR genes remain unknown. PHF8 (PHD (plant homeo domain) finger protein 8) is a JmjC domain-containing protein and its mutations have been found in patients with XLMR and craniofacial deformities. Here we provide multiple lines of evidence establishing PHF8 as the first mono-methyl histone H4 lysine 20 (H4K20me1) demethylase, with additional activities towards histone H3K9me1 and me2. PHF8 is located around the transcription start sites (TSS) of approximately 7,000 RefSeq genes and in gene bodies and intergenic regions (non-TSS). PHF8 depletion resulted in upregulation of H4K20me1 and H3K9me1 at the TSS and H3K9me2 in the non-TSS sites, respectively, demonstrating differential substrate specificities at different target locations. PHF8 positively regulates gene expression, which is dependent on its H3K4me3-binding PHD and catalytic domains. Importantly, patient mutations significantly compromised PHF8 catalytic function. PHF8 regulates cell survival in the zebrafish brain and jaw development, thus providing a potentially relevant biological context for understanding the clinical symptoms associated with PHF8 patients. Lastly, genetic and molecular evidence supports a model whereby PHF8 regulates zebrafish neuronal cell survival and jaw development in part by directly regulating the expression of the homeodomain transcription factor MSX1/MSXB, which functions downstream of multiple signalling and developmental pathways. Our findings indicate that an imbalance of histone methylation dynamics has a critical role in XLMR.


Asunto(s)
Encéfalo/embriología , Encéfalo/enzimología , Cabeza/embriología , Histona Demetilasas/metabolismo , Histonas/metabolismo , Factores de Transcripción/metabolismo , Proteínas de Pez Cebra/metabolismo , Pez Cebra/embriología , Animales , Biocatálisis , Encéfalo/citología , Dominio Catalítico , Ciclo Celular , Línea Celular Tumoral , Supervivencia Celular , ADN Intergénico/genética , Regulación de la Expresión Génica , Histona Demetilasas/genética , Histonas/química , Proteínas de Homeodominio/genética , Humanos , Maxilares/citología , Maxilares/embriología , Lisina/metabolismo , Discapacidad Intelectual Ligada al Cromosoma X/enzimología , Discapacidad Intelectual Ligada al Cromosoma X/genética , Metilación , Neuronas/citología , Neuronas/enzimología , Regiones Promotoras Genéticas , Factores de Transcripción/deficiencia , Factores de Transcripción/genética , Sitio de Iniciación de la Transcripción , Pez Cebra/metabolismo , Proteínas de Pez Cebra/genética
3.
Int J Biol Macromol ; 271(Pt 1): 132718, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38821786

RESUMEN

The CO2-based reversible ionic liquid solution of 1,1,3,3-tetramethylguanidine (TMG) and ethylene glycol (EG) in dimethyl sulfoxide (DMSO) after capturing CO2, (2[TMGH]+[O2COCH2CH2OCO2]2-/DMSO (χRILs = 0.1), provides a sustainable and effective platform for cellulose dissolution and homogeneous utilization. Highly porous cellulose aerogel beads and monoliths were successfully prepared via a sol-gel process by extruding cellulose solution into different coagulation baths (NaOH aqueous solution or alcohols) and exposing the cellulose solution in open environment, respectively, and followed by different drying techniques, including supercritical CO2-drying, freeze-drying and air-drying. The effect of the coagulation baths and drying protocols on the multi-scale structure of the as-prepared cellulose aerogel beads and monoliths were studied in detail, and the sol-gel transition mechanism was also studied by the solvatochromic parameters determination. High specific surface area of 252 and 207 m2/g for aerogel beads and monoliths were achieved, respectively. The potential of cellulose aerogels in dye adsorption was demonstrated.


Asunto(s)
Dióxido de Carbono , Celulosa , Geles , Líquidos Iónicos , Celulosa/química , Líquidos Iónicos/química , Dióxido de Carbono/química , Geles/química , Porosidad , Adsorción , Guanidinas/química , Soluciones , Glicol de Etileno/química , Dimetilsulfóxido/química
4.
Int J Biol Macromol ; 252: 126584, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37648137

RESUMEN

Cellulose graft copolymers having well-defined structures could incorporate the characteristics of both the cellulose skeleton and side chains, providing a new method for the preparation functionalised cellulose derivatives. Herein, a series of multifunctional cellulose grafted, alternating 3,4-dihydrocoumarin (DHC) and epoxide (EPO) copolymers (cell-g-P(DHC-alt-EPO)) were prepared in a metal-free DBU/DMSO/CO2 solvent system without adding additional catalyst. Four examples of cell-g-P(DHC-alt-EPO) with tunable thermal and optical properties were synthesized by copolymerization of DHC with styrene oxide (SO), propylene oxide (PO), cyclohexene oxide (CHO) or furfuryl glycidyl ether (FGE) onto cellulose. The nonconjugated cell-g-P(DHC-alt-EPO) showed UV absorption properties with the maximum absorption peak at 282 nm and 295 nm and photoluminescence performance. A clustering-triggered emission mechanism was confirmed and consistent with DFT theoretical calculations. In DMSO solution, the copolymer (DHCSO5) with DP of 11.64 showed ACQ behaviour as the concentration increased. In addition, DHCSO5 had good antioxidant capacity with an instantaneous radical scavenging activity of 2,2-diphenyl-1-picrylhydrazine (DPPH) up to 65 % at a concentration of 40 mg/ ml and increased to 100 % after 30 min. Thus, the multifunctional cell-g-P(DHC-alt-EPO) materials had a variety of potential applications in the fields of fluorescent printing, bio-imaging, UV- shielding and antioxidants.


Asunto(s)
Dióxido de Carbono , Celulosa , Celulosa/química , Dióxido de Carbono/química , Dimetilsulfóxido , Solventes , Polímeros/química , Compuestos Epoxi/química
5.
Int J Biol Macromol ; 232: 123366, 2023 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-36693609

RESUMEN

Polyhydroxyalkanoates (PHAs) as biodegradable plastics have attracted increasing attention due to its biodegradable, biocompatible and renewable advantages. Exploitation some unique microbes for PHAs production is one of the most competitive approaches to meet complex industrial demand, and further develop next-generation industrial biotechnology. In this study, a rare actinomycetes strain A7-Y was isolated and identified from soil as the first PHAs producer of Aquabacterium genus. Produced PHAs by strain A7-Y was identified as poly(3-hydroxybutyrate) (PHB) based on its structure characteristics, which is also similar with commercial PHB. After optimization of fermentation conditions, strain A7-Y can produce 10.2 g/L of PHB in 5 L fed-batch fermenter, corresponding with 54 % PHB content of dry cell weight, which is superior to the reported actinomycetes species. Furthermore, the phaCAB operon in stain A7-Y was excavated to be responsible for the efficient PHB production and verified in recombinant Escherichia coli. Our results indicate that strain A7-Y and its biosynthetic gene cluster are potential candidates for developing a microbial formulation for the PHB production.


Asunto(s)
Actinobacteria , Polihidroxialcanoatos , Poliésteres/química , Actinomyces , Actinobacteria/genética , Hidroxibutiratos
6.
J Pharm Sci ; 111(3): 690-698, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34774918

RESUMEN

Lipid nanoparticles (LNPs) containing mRNA can deliver genetic material to cells for use as vaccines or protein replacement therapies. We characterized the effect of solution pH on cationic LNPs containing green fluorescent protein (EGFP) mRNA and their transfection efficiency. We compared the structural and colloidal properties of mRNA LNPs with LNPs not containing mRNA and mRNA free in solution. We used a combination of biophysical technique to build a picture of the structure of the lipids and mRNA across pH and temperature in the form of an empirical phase diagram (EPD). A combination of Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry was used to investigate lipid phase behavior. The mRNA-LNPs transition from an inverse hexagonal phase at pH values below the pKa of the cationic lipid to a lamellar phase above the pKa. At higher temperatures the mRNA-LNPs also transitioned from an inverse hexagonal phase to a lamellar phase indicating the inverse hexagonal phase is more thermodynamically favorable. Based on circular dichroism, the mRNA within the LNP has more A form structure at pH values below the lipid pKa than above it. Optical density, zeta potential and dynamic light scattering measurements were used to probe the colloidal stability of the mRNA-LNPs. The particles were larger and more prone to aggregation below the pKa. A stability study was performed to relate the biophysical characteristics to the storage of the particles in solution at 4 and 25 °C. mRNA-LNPs had the highest transfection efficiency and stability at pH values below the pKa. However, there was a trade-off between the stability and aggregation propensity since at very low pH the particles were most prone to aggregation. We performed kinetic experiments to show that the time scale of the pH-dependent phase behavior is slow (6 hour transition) and the transition from lamellar to inverse hexagonal phases is irreversible. This suggests that the lamellar phase is less stable and kinetically trapped. Our findings deepen our structural understanding of mRNA-LNPs and will aid the development of related formulations.


Asunto(s)
Lípidos , Nanopartículas , Cationes , Concentración de Iones de Hidrógeno , Lípidos/química , Liposomas , Nanopartículas/química , ARN Mensajero/química , ARN Mensajero/genética , ARN Interferente Pequeño/genética
7.
Vaccine ; 40(33): 4716-4725, 2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35760737

RESUMEN

BACKGROUND: In recent years, Coxsackievirus A2 (CV-A2) has become one of the main serotypes of enterovirus species A associated with hand, foot and mouth disease (HFMD) in China. It has also caused HFMD epidemics in many countries all over the world. Currently, there are no effective, preventive vaccines against it. METHODS: A CV-A2 strain was isolated in RD cells and then adapted to grow in Vero cells. This is in compliance with guidelines for cell substrates allowed for human vaccines by the Chinese regulatory authority. Groups of newborn Kunming mice were inoculated on day 3 and day 9 using two formulations of candidate vaccines, empty particles and full particles. They were then challenged on day 14 at a lethal dose with a mouse-adapted strain. RESULTS: The mice in the control group all died within 14 days post-challenge whereas most of the mice in the candidate vaccine groups survived. It was found that the titers of neutralizing antibodies was dose-dependent in sera of immunized mice. The results also showed that the vaccine candidates stimulated a strong humoral immune response and protected the mice from disease and death. The virus loads in tissues or organs were significantly reduced and pathological changes were either weak or not observed in the immunized groups compared with those in Al(OH)3 control group. Preliminary mapping of the nucleotide and amino acid residues potentially related to cell tropism of the vaccine strain and virulence of the challenge strain was performed. CONCLUSION: The results showed that the RD cell-isolated and Vero cell-adapted CV-A2 strain is a promising vaccine candidate. This active immunization-challenge mouse model mimics the vaccination and then exposure to wildtype viruses, compared with passive immunization-challenge model, and is invaluable for efficacy evaluation in studies on multivalent vaccines containing CV-A2 against HFMD.


Asunto(s)
Enterovirus Humano A , Enterovirus , Enfermedad de Boca, Mano y Pie , Vacunas Virales , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Chlorocebus aethiops , Enfermedad de Boca, Mano y Pie/prevención & control , Humanos , Inmunidad Humoral , Ratones , Células Vero
8.
Br J Nutr ; 105(7): 1047-54, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21106132

RESUMEN

The aim of the present study was to examine the association between dietary patterns and weight change prospectively. We followed up 1231 adults aged 20 years and older (mean age 49·3 years) from 2002 to 2007. Food intake was assessed at baseline by an FFQ. Factor analysis was used to identify dietary patterns. Nutrient intake was measured by food weighing plus consecutive individual 3 d food records. Body weight and height were measured. The mean 5-year weight gain among all participants was 0·8 (sd 4·7) kg. The mean weight changes across quartiles of the 'traditional' pattern (rice, fresh vegetables, pork and wheat flour) were 2·0, 0·6, 0·6 and 0·0 kg. The corresponding values were 0·4, 0·5, 0·7 and 1·6 kg across quartiles of the 'vegetable-rich' pattern. No significant association between the 'macho' dietary pattern (meat and alcohol), the 'sweet tooth' pattern (drinks and cake) and weight gain was found. In multivariate linear regression, using the first quartile as the reference, participants in the highest quartile of the 'traditional' pattern had a ß of - 2·18 (95 % CI - 2·91, - 1·45) for weight gain. However, the ß from weight change of the highest quartile of the 'vegetable-rich' pattern was 1·00 (95 % CI 0·25, 1·74). In conclusion, the 'traditional' dietary pattern was negatively and the 'vegetable-rich' pattern was positively associated with weight gain in Chinese adults.


Asunto(s)
Dieta , Ingestión de Energía , Aumento de Peso , Adulto , China , Dieta/efectos adversos , Registros de Dieta , Análisis Factorial , Femenino , Estudios de Seguimiento , Humanos , Modelos Lineales , Masculino , Análisis Multivariante , Estudios Prospectivos , Encuestas y Cuestionarios
9.
Bioresour Technol ; 295: 122230, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31669870

RESUMEN

To overcoming the natural recalcitrance of cellulose for glucose production via enzymatic hydrolysis, a new strategy of destroying hydrogen bond donor to reconstruct cellulose's hydrogen bonding network was developed via a mild reversible reaction of cellulose with CO2 catalyzed by organic bases. The reaction dynamics of cellulose with CO2 in the presence of organic bases was studied by using in situ IR. Investigation also included how the organic bases in pretreatment media and pretreatment parameters including CO2 pressure, pretreatment temperature and time affected the physical-chemical structure of cellulose by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Atomic force microscopy (AFM) and subsequent enzymatic scarification of cellulose. The findings showed that dissolution activation efficiency significantly correlated to various parameters, that can be optimized to be the tetramethyl guanidine (TMG)/CO2/DMSO solvent system at 50 °C, 2 MPa of CO2 for 2 h, by which a complete transformation the cellulose crystalline structure from I to II, and 100% glucose yield were achieved. The recyclability and usability are also investigated.


Asunto(s)
Dióxido de Carbono , Celulosa , Hidrólisis , Microscopía Electrónica de Rastreo , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
10.
Anal Chem ; 81(5): 1872-80, 2009 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-19203287

RESUMEN

The development of more efficient utilization of biomass has received increased attention in recent years. Cellulases play an important role in processing biomass through advanced biotechnological approaches. Both the development and the application of cellulases require an understanding of the activities of these enzymes. A new method to determine the activity of cellulase has been developed using a quartz crystal microbalance (QCM) technique. We compare the results from this technique with those from the IUPAC (International Union of Pure and Applied Chemistry) dinitrosalicylic acid (DNS) standard method and also from biccinchoninic acid and ion chromatography methods. It is shown that the QCM technique provides results closer to those obtained by measuring the actual reducing sugars. The elimination of the use of color development in the standard redox methods makes the QCM platform easier to implement; it also allows more flexibility in terms of the nature of the substrate. Finally, validation of the proposed method was carried out by relating the crystallinity of different substrates to the cellulase activity. Numerical values of cellulase activities measured with the QCM method showed that celluloses with higher crystallinity indices were hydrolyzed slower and to a lower extent than those of lower crystallinity indices for the cellulase mixtures examined.


Asunto(s)
Celulasa/metabolismo , Celulosa/metabolismo , Cuarzo/química , Celulasa/química , Cristalización , Electroquímica/métodos , Diseño de Equipo , Modelos Químicos , Nanotecnología , Propiedades de Superficie
11.
Cell Death Dis ; 8(6): e2866, 2017 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-28594402

RESUMEN

Enterovirus 71 (EV71) is the main causative agent of hand, foot and mouth disease (HFMD), which induces significantly elevated levels of cytokines and chemokines, leading to local or system inflammation and severe complications, whereas the underlying regulatory mechanisms and the inflammatory pathogenesis remain elusive. ARRDC4 is one member of arrestins family, having important roles in glucose metabolism and G-protein-coupled receptors (GPCRs) related physiological and pathological processes, however, the function of ARRDC4 in innate immune system is largely unknown. Here we identified that ARRDC4 expression was increased after EV71 infection in THP-1-derived macrophages and verified in EV71-infected HFMD patients and the healthy candidates. The expression level of ARRDC4 was positively correlated with the serum concentration of IL-6, TNF-α and CCL3 in clinical specimens. ARRDC4 interacted with MDA5 via the arrestin-like N domain, and further recruited TRIM65 to enhance the K63 ubiquitination of MDA5, resulting in activation of the downstream innate signaling pathway and transcription of proinflammatory cytokines during EV71 infection. Our data highlight new function of ARRDC4 in innate immunity, contributing to the better understanding about regulation of MDA5 activation after EV71 infection, and also suggest ARRDC4 may serve as a potential target for intervention of EV71-induced inflammatory response.


Asunto(s)
Enterovirus Humano A/inmunología , Infecciones por Enterovirus/inmunología , Inmunidad Innata , Helicasa Inducida por Interferón IFIH1/inmunología , Péptidos y Proteínas de Señalización Intracelular/inmunología , Proteínas de Motivos Tripartitos/inmunología , Ubiquitina-Proteína Ligasas/inmunología , Ubiquitinación/inmunología , Enterovirus Humano A/genética , Infecciones por Enterovirus/genética , Femenino , Células HEK293 , Enfermedad de Boca, Mano y Pie/genética , Enfermedad de Boca, Mano y Pie/inmunología , Humanos , Helicasa Inducida por Interferón IFIH1/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Masculino , Células THP-1 , Proteínas de Motivos Tripartitos/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación/genética
12.
Biomed Res Int ; 2016: 9824827, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27652269

RESUMEN

A microsphere composite made of poly(DL-lactic-co-glycolic acid) (PLGA), mesoporous silica nanoparticle (MSN), and nanohydroxyapatite (nHA) (PLGA-MSN/nHA) was prepared and evaluated as bone tissue engineering materials. The objective of this study was to investigate the synergistic effect of MSN/nHA on biocompatibility as well as its potential ability for bone formation. First, we found that this PLGA-MSN/nHA composite performed good characteristics on microstructure, mechanical strength, and wettability. By cell culture experiments, the adhesion and proliferation rate of the cells seeded on PLGA-MSN/nHA composite was higher than those of the controls and high levels of osteogenetic factors such as ALP and Runx-2 were detected by reverse transcriptase polymerase chain reaction. Finally, this PLGA-MSN/nHA composite was implanted into the femur bone defect in a rabbit model, and its ability to induce bone regeneration was observed by histological examinations. Twelve weeks after implantation, the bone defects had significantly more formation of mature bone and less residual materials than in the controls. These results demonstrate that this PLGA-MSN/nHA composite, introducing both MSN and nHA into PLGA microspheres, can improve the biocompatibility and osteoinductivity of composite in vitro and in vivo and had potential application in bone regeneration.


Asunto(s)
Materiales Biocompatibles/uso terapéutico , Regeneración Ósea/efectos de los fármacos , Microesferas , Ingeniería de Tejidos , Animales , Materiales Biocompatibles/química , Durapatita/química , Durapatita/uso terapéutico , Humanos , Ácido Láctico/química , Ácido Láctico/uso terapéutico , Ácido Poliglicólico/química , Ácido Poliglicólico/uso terapéutico , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Conejos , Dióxido de Silicio/química , Dióxido de Silicio/uso terapéutico
13.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 32(1): 29-35, 2016 Jan.
Artículo en Zh | MEDLINE | ID: mdl-27197477

RESUMEN

OBJECTIVE: To investigate the facial aging analysis of 1200 Han adult people in Dalian with iris diameter, so as to provide reference for facial rejuvenation in Han people. METHODS: 1200 facial digital photographs from the second-generation ID card of China were stratified randomly selected as the research sample, excluding facial deformity, tattooing eyebrow, tattooing lid margin, ptosis, lip grain and eyebrow deformity cases, as well as the cases whose join point of upper eyelid and lower eyelid not exposed at the nasal side. These photos were divided into six cohorts: female aged 18, 38, and 68 years old; and male aged 18, 38, and 68 years old, with 200 cases in each cohort. The individual iris diameter was divided into 20 equal parts in each photograph, with each part marked one unit as individual iris diameter ruler. Ten values were made from a horizontal plane between the medial canthus to ten points at one face ( the line between two medial canthus is used as the horizontal line, circumocular and facial soft tissue were measured with individual iris diameter ruler on the photographs), then the results were analyzed with Adobe Photoshop software. RESULTS: There are statistically significant differences in eyebrow height (36.42 ± 4.22 unit in 18 years old male group, 40.22 ± 6.90 unit in 38 years old male group, 34.83 ± 9.39 unit in 68 years old male group; 37.59 ± 6.72 unit in 18 years old female group, 41.09 ± 5.15 unit in 38 years old female group, 36.84 ± 9.45 unit in 68 years old female group), palpebral fissure height, physiognomic external canthus height, palpebral fissure width, pupil height and other items (P < 0.05). CONCLUSIONS: (1) The brow position rises to the peak level at middle age (38 years old group), then drops down gradually with aging. (2) The physiognomic external canthus moves towards the nasal side and caudal side with aging. (3) Eyeball moves towards caudal side with aging. (4) The soft tissue around bilateral angle of mouth, nasal tip and submaxilla moves towards caudal side with aging. (5) The measurement of individual iris diameter ruler can apply to analyze the aging changes of facial soft tissue, and is more suitable for the case when facial photographs are taken at different distances.


Asunto(s)
Envejecimiento , Cara/anatomía & histología , Adolescente , Adulto , Factores de Edad , Anciano , China/etnología , Estudios de Cohortes , Ojo/anatomía & histología , Cejas/anatomía & histología , Femenino , Humanos , Iris/anatomía & histología , Labio/anatomía & histología , Masculino , Nariz/anatomía & histología , Fotograbar , Rejuvenecimiento , Factores Sexuales
14.
Mar Pollut Bull ; 96(1-2): 434-40, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-26002099

RESUMEN

Forty-three surface sediment samples and one gravity core obtained from the offshore area of the Changjiang River were analyzed for selected heavy metals (Cu, Pb, Zn, Cd, As, Hg) to evaluate the spatial distribution and potential ecological risk during the last century. The results indicated that the sediments are composed of silty sand, sandy silt and silt and were deposited in a relatively stable environment over the last century. The studied marine sediments are fine and easily adsorb heavy metals from aquatic systems. The heavy metal concentrations were found to be enriched in the sediments and were generally closely related to anthropogenic activities. However, the data analysis demonstrated that the levels of heavy metal contamination were below background values during the last century, indicating low ecological risk. Spatially, a higher concentration was found at the entrance to the Changjiang River, while it decreased to the northeast. The vertical distribution of contamination levels and ecological risk can be divided into four periods based on the downcore variation in heavy metals: pre-1940s, 1940s-1970s, 1970s-1990s and the late 1990s to the present. These conclusions form the basis for implementing appropriate policies to protect marine sediment quality.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/análisis , Metales Pesados/análisis , Medición de Riesgo/tendencias , Ríos , Contaminantes Químicos del Agua/análisis , China , Ecología
15.
Zhongguo Gu Shang ; 25(8): 662-6, 2012 Aug.
Artículo en Zh | MEDLINE | ID: mdl-25058959

RESUMEN

OBJECTIVE: To explore surface roughness of bone cement and surround tissue on histological characteristic of induced membranes. METHODS: Bone cements with smooth and rough surface were implanted in radius bone defect, intramuscular and subcutaneous sites of rabbits, and formed induced membranes. Membranes were obtained and stained (HE) 6 weeks later. Images of membrane tissue were obtained and analyzed with an automated image analysis system. Five histological parameters of membranes were measured with thickness,area,cell density,ECM density and microvessel density. Double factor variance analysis was used to evaluate the effect of the two factors on histological characteristics of induced membranes. RESULTS: Membranes can be induced by each kind of bone cement and at all the three tissue sites. In histological parameters of thickness,area and micro vessel,there were significant differences among the membranes induced at different tissue sites (P = 0.000, P = 0.000, P = 0.000); whereas, there were no significant differences in histological parameters of cell density and ECM density (P = 0.734, P = 0.638). In all five histological parameters of membranes, there were no significant differences between the membranes induced by bone cements with different surface roughness (P = 0.506, P = 0.185, P = 0.883, P = 0.093, P = 0.918). CONCLUSION: Surround tissue rather than surface roughness of bone cements can affect the histological characteristics of induced membranes. The fibrocystic number, vascularity, mechanical tension and micro motion of the surround tissue may be closely correlated with the histological characteristics of induced membranes.


Asunto(s)
Cementos para Huesos , Membranas/citología , Ingeniería de Tejidos/métodos , Andamios del Tejido , Animales , Femenino , Conejos , Radio (Anatomía)/citología , Propiedades de Superficie
16.
Br J Pharmacol ; 162(2): 441-51, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20942813

RESUMEN

BACKGROUND AND PURPOSE: Byakangelicin is found in extracts of the root of Angelica dahurica, used in Korea and China as a traditional medicine to treat colds, headache and toothache. As byakangelicin can inhibit the effects of sex hormones, it may increase the catabolism of endogenous hormones. Therefore, this study investigated the effects of byakangelicin on the cytochrome P450 isoform cytochrome (CY) P3A4 in human hepatocytes. EXPERIMENTAL APPROACH: Cultures of human hepatocytes and a hepatoma cell line (Huh7 cells) were used. mRNA and protein levels were measured by quantitative reverse transcription-polymerase chain reaction and Western blot. Plasmid constructs and mutants were prepared by cloning and site-directed mutagenesis. Reporter (luciferase) activity was determined by transient co-transfection experiments. KEY RESULTS: In human primary hepatocytes, byakangelicin markedly induced the expression of CYP3A4 both at the mRNA level (approximately fivefold) and the protein level (approximately threefold) but did not affect expression of human pregnane X receptor (hPXR). In reporter assays, byakangelicin activated CYP3A4 promoter in a concentration-dependent manner (EC50 = 5 µM), and this activation was enhanced by co-transfection with hPXR. Further reporter assays demonstrated that the eNR4 binding element in the CYP3A4 promoter was required for the transcriptional activation of CYP3A4 by byakangelicin. CONCLUSIONS AND IMPLICATIONS: Byakangelicin induced expression and activity of CYP3A4 in human hepatocytes. This induction was achieved by the transactivation of PXR and not by increased expression of PXR. Therefore, byakangelicin is likely to increase the expression of all PXR target genes (such as MDR1) and induce a wide range of drug-drug interactions.


Asunto(s)
Citocromo P-450 CYP3A/biosíntesis , Citocromo P-450 CYP3A/genética , Furocumarinas/farmacología , Hepatocitos/efectos de los fármacos , Receptores de Esteroides/genética , Activación Transcripcional , Adulto , Anciano , Línea Celular Tumoral , Células Cultivadas , Interacciones Farmacológicas/genética , Femenino , Furocumarinas/toxicidad , Hepatocitos/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Mutagénesis Sitio-Dirigida , Receptor X de Pregnano , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Esteroides/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transfección
17.
J Phys Chem B ; 113(44): 14761-8, 2009 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-19827780

RESUMEN

Quartz crystal microgravimetry (QCM) was used to investigate the interactions between cellulase enzymes and model cellulose substrates. The substrates consisted of thin films of cellulose that were spin-coated onto polyvinylamine (PVAm) precoated quartz crystal sensors carrying conductive gold surfaces. In QCM the quartz crystals are piezoelectrically driven and the frequency and dissipation shifts allow monitoring of substrate hydrolysis at various temperatures and enzyme concentrations in situ and in real time. The changes in frequency of cellulose-coated quartz resonators during their incubation in cellulase solutions were related to contributions from the liquid phase properties, the adsorptions of cellulase enzymes, and the hydrolysis of the substrate. Cellulase adsorption was found to be nonspecific and irreversible on gold-, PVAm-, and cellulose-coated quartz crystal sensors. The contribution to frequency shifts due to the bulk fluid properties of the cellulase solutions (at concentrations lower than 0.5 mg/mL) was minimal compared to the frequency shifts produced by cellulase binding. The maximum frequency decreases were fitted to a Langmuir model. The adsorption constant and the maximum adsorption were estimated by the fitting parameters of this model. The hydrolysis process was modeled by using a dose-response model that was then used to estimate the maximum hydrolysis rate, to compare the relative effects of temperature on adsorption and hydrolysis rate, and to obtain the apparent activation energy of cellulose hydrolysis. The hydrolysis rate increased with incubation temperature while apparent adsorption decreased. The apparent activation energy for the hydrolysis of the cellulose films employed was calculated to be 37 kJ/mol.


Asunto(s)
Celulasa/metabolismo , Cuarzo/química , Técnicas Biosensibles , Celulasa/química , Celulosa/química , Celulosa/metabolismo , Oro/química , Hidrólisis , Cinética , Temperatura
18.
Zhonghua Liu Xing Bing Xue Za Zhi ; 23(3): 167-71, 2002 Jun.
Artículo en Zh | MEDLINE | ID: mdl-12411081

RESUMEN

OBJECTIVE: In order to minimize lead pollution and to protect the identified individuals with high blood lead level from lead contamination, an epidemiological study was carried on children living around the village and township-owned lead industries in Tianying town. METHODS: Environmental monitoring: lead levels in air, soil, drinking water and crops were measured. Biological monitoring: 959 children aged 5 - 12 years were selected from villages where the lead smelters located near the residential areas and the battery disassembling was done in some families. The control children (207 pupils) were from other villages without lead exposure. Blood lead, ZnPP and teeth lead were determined. Height, weight and head circle of children and IQ scores were measured. RESULTS: The environment was seriously polluted. The average lead concentrations in air and soils were 8.5 times and 10 times of the MACs (national health standard) respectively. Eighty-five per cent the air samples with lead concentrations higher than the national health standard. Local crops and wheat at farmers' home were also contaminated by lead dust, with. Lead content being 24 times higher than the standard. The mean blood lead and ZnPP levels of children lived in the polluted areas were 496 microgram/L and 9.41 microgram/g Hb respectively. The lead exposure caused adverse effects on children's IQ and physical development. CONCLUSION: It is necessary to remove and reduce currently active sources of lead pollution in the community and to increase public awareness of potential health effects of lead exposure.


Asunto(s)
Contaminación Ambiental/efectos adversos , Residuos Industriales/efectos adversos , Plomo/sangre , Contaminantes Atmosféricos/análisis , Niño , Desarrollo Infantil/efectos de los fármacos , Preescolar , China , Productos Agrícolas/química , Monitoreo del Ambiente/métodos , Contaminación Ambiental/análisis , Femenino , Estado de Salud , Humanos , Residuos Industriales/análisis , Plomo/efectos adversos , Masculino , Contaminantes del Suelo/análisis , Salud Suburbana/normas , Salud Urbana/normas
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