Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
J Viral Hepat ; 24(2): 117-127, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27790803

RESUMEN

Women who inject drugs have been shown to have higher incidence of HIV and risk behaviours than men, but there are conflicting reports about hepatitis C virus (HCV) incidence. We systematically reviewed the literature to examine the female-to-male (F:M) HCV incidence in female and male persons who inject drugs (PWID), and also to explore the heterogeneity (i.e. methodological diversity) in these differences. We searched PubMed and EMBASE for studies published between 1989 and March 2015 for research that reported incidence of HCV infection by sex or HCV incidence F:M rate ratio. A total of 28 studies, which enrolled 9325 PWID, were included. The overall pooled HCV incidence rate (per 100 person-years observation) was 20.36 (95% CI: 13.86, 29.90) and 15.20 (95% CI: 10.52, 21.97) in females and males, respectively. F:M ratio was 1.36:1 (95% CI: 1.13, 1.64) with substantial heterogeneity (I-squared=71.6%). The F:M ratio varied by geographic location from 4.0 (95% CI: 1.80, 8.89) in China to 1.17 (95% CI: 0.95, 1.43) in the U.S. In studies which recruited participants from community settings, the F:M ratio was 1.24 (95% CI: 1.03, 1.48), which was lower than that reported in the clinical settings (1.72, 95% CI: 0.86, 3.45). The number of studies included provided sufficient statistical power to detect sex differences in this analysis. Our findings raise questions and concerns regarding sex differences with respect to the risk of HCV. Both behavioural and biological studies are needed to investigate causes and potential mechanisms as well as sex-specific prevention approaches to HCV infection.


Asunto(s)
Consumidores de Drogas , Hepatitis C/epidemiología , Abuso de Sustancias por Vía Intravenosa/complicaciones , Femenino , Humanos , Incidencia , Masculino , Factores Sexuales
2.
Br J Surg ; 101(13): 1627-36, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25294112

RESUMEN

BACKGROUND: Negative-pressure wound therapy (NPWT) promotes angiogenesis and granulation, in part by strain-induced production of growth factors and cytokines. As their expression profiles are being unravelled, it is pertinent to consider the mode of action of NPWT at the molecular level. METHODS: MEDLINE (January 1997 to present), Embase (January 1997 to present), PubMed (no time limit), the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Register were searched for articles that evaluated the influence of NPWT on growth factor expression quantitatively. RESULTS: Sixteen studies met the inclusion criteria. Tumour necrosis factor expression was reduced in acute and chronic wounds, whereas expression of interleukin (IL) 1ß was reduced in acute wounds only. Systemic IL-10 and local IL-8 expression were increased by NPWT. Expression of vascular endothelial growth factor, fibroblast growth factor 2, transforming growth factor ß and platelet-derived growth factor was increased, consistent with mechanoreceptor and chemoreceptor transduction in response to stress and hypoxia. Matrix metalloproteinase-1, -2, -9 and -13 expression was reduced but there was no effect on their enzymatic inhibitor, tissue inhibitor of metalloproteinase 1. CONCLUSION: Cytokine and growth factor expression profiles under NPWT suggest that promotion of wound healing occurs by modulation of cytokines to an anti-inflammatory profile, and mechanoreceptor and chemoreceptor-mediated cell signalling, culminating in angiogenesis, extracellular matrix remodelling and deposition of granulation tissue. This provides a molecular basis for understanding NPWT.


Asunto(s)
Citocinas/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Terapia de Presión Negativa para Heridas , Cicatrización de Heridas/fisiología , Heridas y Lesiones/terapia , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , Ratas , Porcinos , Heridas y Lesiones/fisiopatología
3.
Sci Rep ; 14(1): 3226, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38331986

RESUMEN

Each of the exchange-correlation functionals in the density functional theory has been customized to particular systems or elements and has unique advantages and disadvantages. In one of the most recent research on exchange-correlation functionals, Chachiyo et al. present a relationship for exchange-correlation functional by assuming the simplest form of electron density. Their utilized electron density causes a systematic inaccuracy in the energy of the molecules since it does not fully account for the variation of the ionization energy for different atoms. We offer a novel relationship for exchange functional that improves the precision of the energy calculations for molecules by using the basic assumptions of the Chachiyo approach and correcting the electron density. Our density is directly related to the atom's ionization energy. Our suggested functional was implemented for 56 molecules composed of atoms from the first, second, and third rows of the periodic table using Siam Quantum package. We discussed about the role of our functional on the reducing the computation error of dipole moment along with total, bonding and zero point energies. We also increased the portion of core electrons to improve the accuracy of the results.

4.
Spinal Cord ; 49(2): 280-4, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20733588

RESUMEN

STUDY DESIGN: Spinal cord injury (SCI) results in alterations in the regulation of many genes that may influence neuronal death and the subsequent loss of motor function and neuropathic pain. The subtype expression mRNA levels of glycine receptors (GlyRs) after SCI are unknown. METHODS: Using real-time reverse transcription PCR, this study analyzed changes in the mRNA abundance of the four major GlyR subunits (α13 and ß) at 6, 24 h and 3, 7 and 10 days after SCI in adult male rats. SCI was induced at the T9 level by transection. RESULTS: Our results show a complicated temporal and spatial pattern of alteration in GlyR mRNA expression levels after SCI. Temporal and spatial variations with different degrees and direction (up or downregulation) of expression alteration were observed. The greatest variation was seen in GlyRα1, whereas GlyRα2 was downregulated in all regions following SCI. CONCLUSION: This study shows that alteration in GlyR expression starts as early as 6 h after SCI. The most significant points of this research are temporal elevation of GlyRα1 and continuous reduction of GlyRα2. Alterations in GlyR expression within the spinal cord may have a key role in the development of pathological pain. Therefore, control of GlyR expression could represent a novel therapeutic avenue for the development of new painkiller agents in SCI.


Asunto(s)
Regulación de la Expresión Génica/fisiología , ARN Mensajero/biosíntesis , Receptores de Glicina/biosíntesis , Traumatismos de la Médula Espinal/genética , Animales , Modelos Animales de Enfermedad , Masculino , Subunidades de Proteína/biosíntesis , Subunidades de Proteína/genética , Ratas , Ratas Wistar , Receptores de Glicina/química , Receptores de Glicina/genética , Traumatismos de la Médula Espinal/metabolismo
5.
Int Endod J ; 44(6): 499-504, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21276017

RESUMEN

AIM: To determine mRNA expression levels of Nav 1.8 in inflamed pulps of rats. METHODOLOGY: Inflammation was induced by creating pulp exposures in rat incisors. Histopathological changes in the induced pulpitis were evaluated 1, 3, 7 and 10 days after exposure. Using real-time PCR, the relative mRNA expression levels of Nav 1.8 in the inflamed rat dental pulp was determined. RESULTS: At day 1, no inflammation was evident in the pulp tissue, whereas increased levels of inflammatory responses were identified at day 3 and day 7. No pulpal inflammation was evident in day 10 or in the control group. Nav 1.8 was expressed in the rat dental pulp and increased at day 3 and day 7. Time course study of dental pulp inflammation indicated that differences in relative mRNA expression levels of Nav 1.8 were correlated with the severity of inflammation. CONCLUSIONS: Nav 1.8 channels seem to be expressed significantly more under a temporal control so as to be associated with a severity of inflammation during pulpitis. As Nav 1.8 has been considered to have a role in neuropathic pain, its expression within dental pulp may contribute to the pathophysiology of tooth pain.


Asunto(s)
Pulpitis/metabolismo , ARN Mensajero/metabolismo , Canales de Sodio/metabolismo , Animales , Modelos Animales de Enfermedad , Inflamación/genética , Inflamación/metabolismo , Estudios Longitudinales , Masculino , Canal de Sodio Activado por Voltaje NAV1.8 , Ratas , Ratas Wistar , Canales de Sodio/genética
6.
Public Health ; 125(9): 577-84, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21855096

RESUMEN

OBJECTIVES: To undertake a fresh examination of the relationship between income inequality and population health for a group of Islamic countries using recent information derived from data resource sites from the World Bank and Islamic countries. STUDY DESIGN: Cross-sectional data on different measures of income distribution (prosperity, health care, women's role and environment) and indicators of population health were used to illuminate this issue. METHODS: The relationship between income inequality and population health for a group of Islamic countries was tested using recent information derived from data resource sites from the World Bank and Islamic countries. After consideration of previous studies, seven dependent variables were determined and tested in six equation formats. RESULTS: According to the equations, the urban population percentage and gross domestic product are the most important significant variables that affect life expectancy and the infant mortality rate in Islamic countries. The income distribution coefficient, regardless of the type of measure, was almost insignificant in all equations. CONCLUSIONS: In selected Islamic countries, income level has a positive effect on population health, but the level of income distribution is not significant. Among the other dependent variables (e.g. different measures of income distribution, health care, role of women and environment), only environment and education had significant effects. Most of the Islamic countries studied are considered to be poorly developed.


Asunto(s)
Países en Desarrollo , Estado de Salud , Renta , Islamismo , Estudios Transversales , Femenino , Producto Interno Bruto , Humanos , Lactante , Mortalidad Infantil , Recién Nacido , Esperanza de Vida , Factores Socioeconómicos
7.
Acta Paediatr ; 99(2): 209-14, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19839963

RESUMEN

AIM: The objective of this retrospective study is to compare the medical treatment of neonatal narcotic abstinence syndrome with clonidine and chloral hydrate with the commonly used combination therapy of morphine and phenobarbital. METHODS: From 1998 to 2008, a total of 133 newborns suffering from neonatal narcotic abstinence syndrome were treated at our clinic. All of these patients were born to mothers who had received methadone substitution for drug addiction during the course of pregnancy. RESULTS: Twenty-nine patients received clonidine and chloral hydrate, and 64 patients were treated with morphine and phenobarbital for abstinence syndrome. The duration of treatment was significantly shorter in the clonidine/chloral hydrate group (median: 14 days vs. 35 days). Correspondingly, the period of hospitalization was also considerably shorter in the clonidine/chloral hydrate group (median: 32 days vs. 44 days). In addition, patients in the clonidine/chloral hydrate group exhibited markedly reduced withdrawal symptoms. CONCLUSION: This study suggests that a treatment of neonatal abstinence syndrome with clonidine in omission of opiates is possible without causing short-term adverse cardiovascular effects. Considering the retrospective design of the study, controlled and prospective trials are needed.


Asunto(s)
Hidrato de Cloral/uso terapéutico , Clonidina/uso terapéutico , Hipnóticos y Sedantes/uso terapéutico , Metadona/efectos adversos , Síndrome de Abstinencia Neonatal/tratamiento farmacológico , Presión Sanguínea/efectos de los fármacos , Quimioterapia Combinada , Femenino , Humanos , Recién Nacido , Tiempo de Internación/estadística & datos numéricos , Morfina/uso terapéutico , Fenobarbital/uso terapéutico , Embarazo , Estudios Retrospectivos , Resultado del Tratamiento
8.
Acta Gastroenterol Belg ; 83(3): 488-490, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33094600

RESUMEN

BACKGROUND: Biliary system ascariasis can be a rare cause of acute abdomen. PATIENT REPORT: A 70-year-old woman presented with abdominal pain for two weeks. She complained of a right upper quadrant (RUQ) pain, intermittent vomiting and weight loss. Physical examination showed RUQ and epigastric tenderness without rebound tenderness or guarding. Laboratory finding exhibited leukocytosis and mildly elevated liver enzymes. RESULTS: Abdominal sonography showed distended gallbladder and a tubular lesion inside the common bile duct (CBD) in favor of a parasitic lesion. A large ascaris roundworm and blood clots were extracted from the CBD by endoscopic retrograde cholangiopancreatography and sphincterotomy. After 7 days, the disease process was complicated with a subhepatic abscess formation which was managed conservatively. Finally, the patient was discharged home in fair condition after 12 days of hospitalization. CONCLUSIONS: Ascariasis should be considered in endemic areas and early endoscopic intervention and medical therapy can be effective for extrahepatic involvement.


Asunto(s)
Absceso , Ascariasis , Absceso/etiología , Anciano , Ascariasis/complicaciones , Ascariasis/diagnóstico , Ascariasis/diagnóstico por imagen , Colangiopancreatografia Retrógrada Endoscópica , Conducto Colédoco/diagnóstico por imagen , Conducto Colédoco/cirugía , Femenino , Humanos , Ultrasonografía
9.
Anticancer Res ; 27(4B): 2197-207, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17695504

RESUMEN

A host-mediated assay system for detection of the transforming activity of different chemical carcinogens on peritoneal macrophages has been previously established. Directly, as well as indirectly acting carcinogenic substances administered intraperitoneally to NMRI mice could be examined in this way. Resident macrophages were recovered by peritoneal lavage from treated and untreated mice and cultured in soft agar. After 5-6 days normal and transformed cells could be distinguished. By the use of this system an immortalized macrophage-like cell line was derived from the peritoneal cells of NMRI mice treated with 17alpha-ethinylestradiol. This cell line enabled us to perform additional investigations on the underlying molecular effects of 17alpha-ethinylestradiol, such as detection of the transformation specific polypeptides as surrogate markers for transformation. The investigation reported here describes the cell-transforming and oncogenic potential of 17alpha-ethinylestradiol.


Asunto(s)
Transformación Celular Neoplásica/inducido químicamente , Etinilestradiol/toxicidad , Animales , Pruebas de Carcinogenicidad/métodos , Procesos de Crecimiento Celular/efectos de los fármacos , Línea Celular Transformada , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Macrófagos Peritoneales/efectos de los fármacos , Masculino , Ratones , Proto-Oncogenes
11.
Anticancer Res ; 26(6B): 4203-12, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17201134

RESUMEN

The host-mediated in vitro/in vivo assay system was used to evaluate the tumorigenic potential of the aromatic nitro compound 2-nitroanisole (2-NA). After intraperitoneal administration of the compound, resident macrophages were recovered by peritoneal lavage from treated and untreated mice and cultured in soft agar. 2-NA was shown to be carcinogenic, and the tumorigenic potential was evaluated. Additionally, by establishment of a transformed peritoneal macrophage cell line, the underlying molecular mechanism of 2-NA's carcinogenic effect was studied.


Asunto(s)
Anisoles/farmacología , Carcinógenos/farmacología , Animales , Anisoles/química , Carcinógenos/química , Línea Celular , Proliferación Celular/efectos de los fármacos , Electroforesis en Gel de Poliacrilamida , Macrófagos/efectos de los fármacos , Masculino , Ratones , Relación Estructura-Actividad
12.
J Colloid Interface Sci ; 466: 227-37, 2016 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-26724706

RESUMEN

In this study, a new method has developed for the synthesis of Ag/AgBr/Graphene-oxide (Ag/AgBr/GO) nanocomposite with high adsorption capacity and high photocatalytic activity in degradation of methyl orange (MO). In this method, ultrasound was applied in the synthesis and it was facilitated the process. The samples prepared under ultrasound were shown as Ag/AgBr/GO-U, and the samples under conventional method as Ag/AgBr/GO-C. The results of FT-IR, XRD, Raman, DRS and SEM confirmed the structure of the nanocomposites very well. Ultrasound played a key role in the formation of nanocomposite with smaller size of GO sheets and particles. Different amount of GO was used in the nanocomposite composition and their photocatalytic activities were compared. The MO in solution was completely degraded in 15 min, 30 min, and 45 min with Ag/AgBr/GO-U-1 that contained 1 mg mL(-1) GO, Ag/AgBr/GO-U-0.5 that contained 0.5 mg mL(-1) GO and Ag/AgBr/GO-C-0.5 that contained 0.5 mg mL(-1) GO, respectively. The chemical oxygen demand (COD) measurements displayed a complete mineralization in 30 min for Ag/AgBr/GO-U-0.5. The data obtained from the degradation experiments were fitted to the first-order kinetics and the adsorption obeyed the Langmuir model. The nanocatalyst did not exhibit significant loss of activity even after four cycles of successive uses. To determine the mechanism of photocatalytic degradation of MO, different scavengers were used. Based on the results, the superoxide radical, hydroxyl radical and hole had a key role in the degradation process. The Ag/AgBr/GO-U-1 nanocomposite exhibited the highest photocatalytic activity due to its high adsorption capacity and enhanced charge transfer.

13.
Artículo en Inglés | MEDLINE | ID: mdl-26971027

RESUMEN

Three derivatives of α,ß unsaturated amides have been successfully synthesized via Ugi-four component (U-4CR) reaction. The interactions of the amides with calf thymus deoxyribonucleic acid (ct-DNA) have been investigated in the Tris-HCl buffer (pH=7.4) using viscometric, spectroscopic, thermal denaturation studies, and also molecular docking. By UV-Vis absorption spectroscopy studies, adding CT-DNA to the compound solution caused the hypochromism indicates that there are interactions between the compounds and DNA base pairs. In competitive fluorescence with methylene blue as an intercalator probe, adding compounds to DNA-MB solution caused an increase in emission spectra of the complex. This could be because of compound replacing, with similar binding mode of MB, between the DNA base pairs due to release of bonded MB molecules from DNA-MB complex. Thermal denaturation studies and viscometric experiments also indicated that all three investigated compounds bind to CT-DNA by non-classical intercalation mode. Additionally, molecular docking technique predicted partial intercalation binding mode for the compounds. Also, the highest binding energy was obtained for compound 5a. These results are in agreement with results obtained by empirical methods.


Asunto(s)
Amidas/química , Amidas/farmacología , ADN/metabolismo , Sustancias Intercalantes/química , Sustancias Intercalantes/farmacología , Amidas/síntesis química , Animales , Bovinos , Dicroismo Circular , Sustancias Intercalantes/síntesis química , Simulación del Acoplamiento Molecular , Termodinámica
14.
Int J Biol Macromol ; 78: 112-21, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25858880

RESUMEN

An oral delivery system intended for treatment of colon cancer in HT29 cancerous cells was investigated by encapsulating hSET1 antisense and SN38 anticancer in nanoparticles based on cysteine trimethyl chitosan (cysTMC) and carboxymethyl dextran (CMD). Studies have shown hSET1 as the main type of histone methyltransferase (HMT) complex, is significantly overexpressed in malignant cells. In this study, hSET1 antisense was employed to inhibit gene expression. Additionally, SN38 was incorporated into nanoparticles to enhance the efficiency of the system by inhibition of topoisomerase 1. CysTMC was synthetized and characterized by (1)H NMR and FTIR. Nanoparticles were prepared through complexation of CMD and cysTMC. Particle size and surface charge was 100-150 nm and 17-21 mV respectively with drug content of around 2.6%. Gel electrophoresis assay proved the stability of antisense in simulated gastric and intestinal fluids. Nanoparticles showed high mucoadhesion and glutathione responsive release. Cellular uptake was observed by confocal microscopy and quantified by flow cytometry. Cytotoxicity of NPs was assessed using MTT assay. Results showed hSET1/SN38 nanoparticles had significantly higher cytotoxicity against HT29 cells compared with nanoparticles containing SN38, free SN38 or naked hSET1. Therefore, present system could be considered an effective combination therapy of highly hydrophobic SN38 and hSET1.


Asunto(s)
Camptotecina/análogos & derivados , N-Metiltransferasa de Histona-Lisina/genética , Nanopartículas/química , Oligonucleótidos Antisentido/administración & dosificación , Administración Oral , Animales , Camptotecina/administración & dosificación , Línea Celular Tumoral , Quitosano/química , Neoplasias del Colon/patología , Neoplasias del Colon/terapia , Modelos Animales de Enfermedad , Portadores de Fármacos/química , Liberación de Fármacos , Estabilidad de Medicamentos , Humanos , Irinotecán , Ratones , Nanopartículas/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Ensayos Antitumor por Modelo de Xenoinjerto
15.
Anticancer Res ; 20(1A): 283-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10769668

RESUMEN

Analysis of protein secretion was performed for a macrophage-like cell line, which was established from the peritoneal cells of NMRI mice treated with 17 alpha-ethinylestradiol. The protein secretion pattern was investigated by computerized analysis of high resolution two-dimensional gel electrophoresis (2-D PAGE) and compared to that of control macrophages, intraperitoneally activated by bacterial lipopolysaccharide. The transformed cells encode a number of low molecular weight proteins (10-20 kDa), which were not observed in control cells under identical experimental conditions. In conclusion the transformation of peritoneal macrophages by 17 alpha-ethinylestradiol leads to an upregulation of polypeptides, in particular of low molecular weight proteins. A high similarity between the induced low molecular weight protein secretion by macrophages of 17 alpha-ethinylestradiol-treated and that of 2,3,7,8-tetrabromodibenzo-p-dioxin-treated mice was found.


Asunto(s)
Transformación Celular Neoplásica/inducido químicamente , Etinilestradiol/toxicidad , Macrófagos Peritoneales/efectos de los fármacos , Proteínas de Neoplasias/metabolismo , Animales , Células Cultivadas , Dioxinas/toxicidad , Electroforesis en Gel Bidimensional , Procesamiento de Imagen Asistido por Computador , Lipopolisacáridos/farmacología , Activación de Macrófagos/efectos de los fármacos , Macrófagos Peritoneales/metabolismo , Masculino , Ratones , Ratones Endogámicos , Peso Molecular , Proteínas de Neoplasias/química , Proteínas de Neoplasias/aislamiento & purificación , Organismos Libres de Patógenos Específicos , Técnica de Sustracción
16.
Anticancer Res ; 12(6B): 2053-60, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1295448

RESUMEN

We have developed a host-mediated assay system for detection of the transforming activity of chemical carcinogens on peritoneal macrophages, directly, as well as indirectly acting carcinogenic substances administered intraperitoneally to NMRI mice could be examined in this way. Resident macrophages were recovered by peritoneal lavage from treated and untreated mice and cultured in soft agar. After 5-6 days normal and transformed cells could be distinguished. Statistical analysis comparing cells from 2, 3, 7, 8-tetrachlorodibenzo-dioxin (TCDD)-treated animals with those from control mice proved that the test is positive at least on a significance level of 5%, using the t-test. TCDD revealed a cell-transforming potential that showed a dose-dependent response in this host-mediated assay. The co-carcinogenic activity of TCDD was established in experiments with diphenylhydantoin. Low doses of diphenylhydantoin which did not exhibit any transforming potential in our system gained a high oncogenic potential by the simultaneous administration of low doses of TCDD, which also had no transforming activity. We have compared the cell transforming potential of TCDD with its bromo analog TBrDD. The cell transforming potential of TCDD is 7 times that of TBrDD. We have succeeded in establishing a permanent cell lined from mice treated with TBrDD. The oncogenicity of this cell line was tested in athymic nu/nu mice. Animals treated subcutaneously with these cells (1 x 10(6) cells) developed tumors at the injection site. Using monospecific antibodies to tumor necrosis factor alpha (TNF-alpha), we have found that TCDD stimulates the secretion of TNF-alpha. The experimental data reported here lead to the conclusion that TCDD has a carcinogenic as well as a co-carcinogenic activity and has the property to induce TNF-alpha.


Asunto(s)
Carcinógenos/farmacología , Transformación Celular Neoplásica , Dioxinas/farmacología , Macrófagos/efectos de los fármacos , Dibenzodioxinas Policloradas/farmacología , Animales , Carcinógenos/toxicidad , Dioxinas/toxicidad , Técnicas In Vitro , Macrófagos/citología , Macrófagos/patología , Masculino , Ratones , Ratones Endogámicos , Ratones Desnudos , Fenitoína/farmacología , Dibenzodioxinas Policloradas/toxicidad , Valores de Referencia , Acetato de Tetradecanoilforbol/toxicidad
17.
Talanta ; 36(12): 1300-2, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18964908

RESUMEN

The complexation reactions between murexide and Co(2+), Ni(2+) and Cu(2+) in C(2)H(5)OH-H(2)O mixtures have been investigated spectrophotometrically. The formation constants of the 1:1 complexes formed increase in the order Co(2+) < Ni(2+) < Cu(2+) for all solvent mixtures studied, and log K(f) is a linear function of the mole fraction of ethanol. The heat of complexation was determined calorimetrically for the nickel and copper complexes. The values of DeltaH degrees and DeltaS degrees are solvent-dependent, and all three complexes have negative DeltaH degrees and positive DeltaS degrees values.

18.
Rofo ; 176(6): 837-45, 2004 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-15173976

RESUMEN

PURPOSE: To provide reference values for MRI-based flow measurements in the main pulmonary artery in healthy children. MATERIALS AND METHODS: In 98 healthy children (age: 3 - 17 years, median: 11 years), the main pulmonary artery was examined using MRI-based flow measurements with high temporal resolution (9.6 ms per cardiac phase). RESULTS: The acceleration time revealed a distinct age dependency and varied between 90 and 155 ms (mean: 124 ms +/- 14). The relative acceleration time (related to the RR-interval) varied between 12.7 and 27 % (mean: 18 % +/- 2.6). The mean values and the standard deviations for the determined values were as follows: cardiac output (5.4 l/min +/- 1.4), cardiac output normalized to the body surface area (4.2 [l/min]/m(2) +/- 0.8), average systolic flow velocity (66 cm/s +/- 12), maximum systolic flow (309 ml/s +/- 79), mean flow (110 ml/s +/- 30), distensibility of the wall of the main pulmonary artery (79 % +/- 26), peak velocity (96 cm/s +/- 15), pressure gradient along the pulmonary valve (3.8 mm Hg +/- 1.2), stroke volume (63.2 ml +/- 17.9), acceleration volume (23.7 ml +/- 8.7), maximum acceleration of flow (4924 ml/s(2) +/- 1431), and reverse volume (0.2 ml +/- 0.3). CONCLUSIONS: The acquired values of reference are applicable to all pediatric patients and serve as a framework for the communication between the radiologist and the pediatric cardiologists. High temporal resolution of the measurement sequence is mandatory. Noticeable deviations of these values should induce additional (probably invasive) evaluation.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Arteria Pulmonar/fisiología , Pruebas de Función Respiratoria , Adolescente , Velocidad del Flujo Sanguíneo , Niño , Preescolar , Humanos , Valores de Referencia , Análisis de Regresión , Volumen Sistólico , Sístole
19.
J Colloid Interface Sci ; 432: 19-25, 2014 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-25046404

RESUMEN

For the first time, this work reports a facile sonochemical route in the synthesis of graphene oxide nanosheets (GO) via oxidation of graphite (G). The synthesis of GO was carried out in a fast way under ultrasonic bath irradiation (GO-U). In comparison, the synthesis of GO via classical method (GO-C) was done under the same conditions as ultrasonic method. The products were completely different and the oxidation did not happen the same as way as ultrasonic method. Furthermore, GO was synthesized based on classical approach that most commonly used (GO-C'), not under the same conditions as ultrasonic method. The GO sheets were characterized using UV-Vis, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), thermal gravimetry (TG), and Raman spectroscopy techniques. The XRD confirms that the spaces between GO-U and GO-C' sheets were higher than graphite. Also, XRD indicated that the GO-U has fewer sheets rather than GO-C'. The TEM observations were confirmed the synthesis of nanosheets. The UV-Vis results were shown the absorption peaks at 230nm for GO-U and GO-C', at 245nm for GO-C, and at 255nm for G. The blue shift in GO-U with respect to G and GO-C can be interpreted based on the higher character of sp(3)/sp(2) in GO-U than G and GO-C. The FT-IR presents the oxygenated functional groups on graphene oxide sheets. A reduction in size of the in-plane sp(2) domains was observed by Raman spectrum. The BET analysis for G, GO-U and GO-C' confirmed that GO-U has a highest specific surface area among all the samples. Therefore, the ultrasonic bath method even with low intensity has a fundamental role in the synthesis of graphene oxide nanosheets and it is relatively fast, simple, cost-effective and efficient as compared to the classical method.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA