Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Indian J Med Microbiol ; 47: 100490, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37890412

RESUMEN

BACKGROUND: Salivary shedding of SARS-CoV-2 is a known entity and its role has been established in transmission of the disease. The present study was performed to evaluate the duration of viral shedding in saliva in COVID-19 patients and its variation among symptomatic and asymptomatic patients with or without co-morbidities. METHODS: The present prospective observational study was conducted at the COVID-19 care hospital associated with primary to tertiary care in New Delhi, India. A total of 124 COVID-19 confirmed cases enrolled in two phases (January-March 2021; April-June 2021) who consented for 48hrly saliva and nasopharyngeal swab (NPS) specimens till discharge from the hospital for SARS-CoV-2 detection were included. The specimens obtained were tested for SARS-CoV-2 by Real-Time PCR. RESULTS: The sensitivity and the specificity of RT-PCR on saliva were 81.7 â€‹% and 85.0 â€‹%, respectively. The sensitivity of saliva-based PCR was comparable in symptomatic and asymptomatic patients (81.6 â€‹% vs 82.1 â€‹%). The sensitivity of saliva-based PCR markedly increased in the second phase of enrollment as compared to the first phase (92.6 â€‹% vs 78.5 â€‹%) indicating higher level of salivary shedding by the delta variant of SARS-CoV-2. The sensitivity of PCR on saliva was the highest up to day seven of illness. The median duration of RNA shedding in saliva was comparable among the symptomatic and asymptomatic patients. The severity of the disease was not associated with the duration of SARS-CoV-2 shedding in saliva. CONCLUSIONS: SARS-CoV-2 shedding in saliva continued till seven days in large number of patients including asymptomatic patients. Saliva is non-inferior to NPS specimen in the diagnosis of SARS-CoV-2. Saliva specimen is recommended as a good alternate to NPS for SARS-CoV-2 testing.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Prueba de COVID-19 , Saliva , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Técnicas de Laboratorio Clínico , ARN Viral/genética , ARN Viral/análisis , Manejo de Especímenes , Nasofaringe
2.
Malays J Pathol ; 35(2): 181-3, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24362482

RESUMEN

Testicular microlithiasis (TM) is a rare benign condition with presence of multiple small microcalcifications in the seminiferous tubules. Though the aetiology is unknown, TM has been described in association with a variety of urological conditions. We report the clinico-pathological features of a 12-year-old male child who underwent orchidectomy for undescended testis. Histopathological examination of the excised testis showed multiple small intratubular calcifications without any evidence of testicular neoplasia. TM is an unusual phenomenon that should be kept in mind while evaluating testicular biopsies. Though it behaves in a benign manner in most of the cases, patients with positive family history of testicular cancer should be followed-up for testicular tumour.


Asunto(s)
Cálculos/complicaciones , Cálculos/patología , Criptorquidismo/complicaciones , Criptorquidismo/patología , Enfermedades Testiculares/complicaciones , Enfermedades Testiculares/patología , Niño , Humanos , Masculino
3.
J Hazard Mater ; 161(2-3): 1323-9, 2009 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-18541366

RESUMEN

A new chelating polymeric extraction chromatographic resin was prepared by chemical anchoring of N,N'-dimethyl-N,N'-dibutyl malonamide (DMDBMA) with chloromethylated Merrifield resin((R)). The grafted resin exhibited stronger binding for hexavalent and tetravalent actinides such as U(VI), Th(IV) and Pu(IV) over trivalent actinides, viz. Am(III) and Pu(III). Batch studies on solid phase extraction performed over a wide range of acid solution (0.01-6M HNO(3)) revealed that ternary mixer of uranium, americium and plutonium or thorium, americium and plutonium could be separated from each other at 1M HNO(3). Desorption of U(VI), Pu(IV) and Am(III) from the loaded resin was efficiently carried out using 0.1M alpha-HIBA, 0.25M oxalic acid and 0.01M EDTA, respectively. Quantitative pre-concentration of actinide ions such as Th(IV) and U(VI) was possible from 3M HNO(3) solution. The practical utility of the grafted resin was evaluated by uranium sorption measurements in several successive cycles. The sorption efficiency of the resin with respect to uranyl ion remained unchanged even after 30 days of continuous use. The surface morphology of the resin was monitored with the help of scanning electron microscopy (SEM) technique.


Asunto(s)
Elementos de Series Actinoides/análisis , Malonatos/química , Poliestirenos/química , Compuestos de Vinilo/química , Americio/química , Técnicas de Química Analítica/métodos , Iones , Microscopía Electrónica de Rastreo , Modelos Químicos , Plutonio/química , Soluciones , Espectrofotometría Ultravioleta/métodos , Torio/química , Uranio/química
4.
Emerg Radiol ; 16(6): 497-9, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19050947

RESUMEN

In recent years, intimal injuries to the aorta (minimal aortic injuries) have been diagnosed more frequently. We report the first case of pulmonary artery intimal injury in the setting of blunt trauma. We propose a number of theories regarding the pathogenesis, outcome, and treatment of pulmonary artery intimal injuries, drawing inferences from aortic intimal injuries. We conclude with a discussion on differentiating pulmonary artery intimal injury from the more common (but still rare) pulmonary artery dissection, using our case as an example.


Asunto(s)
Angiografía/métodos , Arteria Pulmonar/lesiones , Tomografía Computarizada por Rayos X/métodos , Túnica Íntima/lesiones , Heridas no Penetrantes/diagnóstico por imagen , Medios de Contraste , Resultado Fatal , Humanos , Masculino , Persona de Mediana Edad
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 73(2): 348-52, 2009 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-19329353

RESUMEN

N,N,N',N'-tetraoctyl diglycolamide (TODGA) has been identified as one of the promising extractants for the partitioning of minor actinides from high-level nuclear waste solutions. Solvent extraction studies have shown that stoichiometry of the extracted species of Eu(3+) with TODGA depend on the nature of diluent. Time resolved luminescence spectroscopy (TRLS) has been employed to investigate the complexation of Eu(3+) with TODGA under different experimental conditions. The effects of different experimental parameters such as aqueous phase acidity, nature of diluent, and TODGA concentration on the luminescence lifetime of Eu(3+) ions have been investigated. The lifetime measurements of the complexed fraction of Eu(3+) with TODGA suggested the absence of water molecules in the inner coordination sphere of the metal ion in different solvents. In ethanol-water (60/40%) mixture, the complexation of Eu(3+) with TODGA under varying ligand-to-metal ratios suggested the formation of 1:1, 1:2, and 1:3 species, viz., Eu(TODGA)(3+), Eu(TODGA)(2)(3+), and Eu(TODGA)(3)(3+), respectively. The conditional stability constants logbeta(1), logbeta(2), and logbeta(3) were calculated as 6.1+/-0.5, 10.8+/-0.7, and 14.3+/-0.6, respectively. The nature of diluent did not influence the luminescence spectra of Eu(3+) in the presence of TODGA.


Asunto(s)
Europio/química , Glicolatos/química , Concentración de Iones de Hidrógeno , Luminiscencia , Ácido Nítrico/química , Solventes/química , Espectrometría de Fluorescencia
6.
J Hazard Mater ; 156(1-3): 129-34, 2008 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-18242840

RESUMEN

Diffusion coefficients of sodium in barium borosilicate glasses having varying concentration of barium were determined by heterogeneous isotopic exchange method using (24)Na as the radiotracer for sodium. The measurements were carried out at various temperatures (748-798 K) to obtain the activation energy (E(a)) of diffusion. The E(a) values were found to increase with increasing barium content of the glass, indicating that introduction of barium in the borosilicate glass hinders the diffusion of alkali metal ions from the glass matrix. The results have been explained in terms of the electrostatic and structural factors, with the increasing barium concentration resulting in population of low energy sites by Na(+) ions and, plausibly, formation of more tight glass network. The leach rate measurements on the glass samples show similar trend.


Asunto(s)
Bario/química , Vidrio , Sodio/química , Rastreo Diferencial de Calorimetría , Difusión , Electricidad Estática , Temperatura
7.
J Chromatogr A ; 1123(1): 26-30, 2006 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-16709417

RESUMEN

Sorption of Am3+ and Eu3+ onto an extraction chromatographic resin material, prepared by impregnating purified bis(2,4,4-trimethylpentyl)dithiophosphinic acid (commercially available as Cyanex 301) into Chromosorb W, was investigated. Separation factor (S.F. = K(d,Am)/K(d,Eu)) values tend to increase in the presence of complexing agents such as thiocyanate and nitrate. In presence of 1 M NaNO3 in the aqueous phase, a S.F. value of approximately 1000 was obtained. The nature of extracted species was ascertained by carrying out the sorption studies at different aqueous phase pH. A column made from 300 mg of the resin material was used for the separation of Am3+ and Eu3+. A synthetic solution containing 1x10(5) cpm each of Am3+ and Eu3+ when loaded on to the column, >99% Eu was eluted out in 60 mL of 1 M NaNO3 at a pH of 3.2 while Am was eluted out using 5 mL of 1 M HNO3. The performance of the resin material was found to be reasonably good even after three cycles.


Asunto(s)
Americio/aislamiento & purificación , Cromatografía Liquida/métodos , Europio/aislamiento & purificación , Compuestos Organofosforados/química , Compuestos Organotiofosforados
8.
Indian Pediatr ; 53(4): 341-2, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27156550

RESUMEN

BACKGROUND: Management of pyothorax and pneumothorax requires aspiration and/or intercostal drainage. CASE CHARACTERISTICS: We present two cases which were complicated by instrument-related events resulting in breakage of needle or intercostal drainage tube resulting in pleural foreign body. INTERVENTION/OUTCOME: The patients were stabilized and the foreign bodies retrieved using thoracoscopic approach. MESSAGE: Thoracoscopy provides a minimally invasive approach to deal with pleural foreign bodies.


Asunto(s)
Cuerpos Extraños , Enfermedad Iatrogénica , Toracoscopía , Tubos Torácicos/efectos adversos , Preescolar , Empiema Pleural/etiología , Femenino , Cuerpos Extraños/complicaciones , Cuerpos Extraños/diagnóstico , Cuerpos Extraños/cirugía , Humanos , Recién Nacido , Masculino , Agujas/efectos adversos
9.
Indian J Med Microbiol ; 34(4): 520-525, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27934835

RESUMEN

The antimicrobial trends over 6 years were studied, and the effect of revised Clinical Laboratory Standards Institute (CLSI) breakpoints (2012) for ciprofloxacin susceptibility reporting in typhoidal Salmonellae was determined. A total of 874 (95.4%) isolates were nalidixic acid-resistant (NAR). Using the CLSI 2011 guidelines (M100-S21), 585 (66.9%) isolates were ciprofloxacin susceptible. The susceptibility reduced to 11 (1.25%) isolates when interpreted using 2012 guidelines (M100-S22). Among the forty nalidixic acid susceptible (NAS) Salmonellae, susceptibility to ciprofloxacin decreased from 37 isolates (M100-S21) to 12 isolates (M100-S22). The 25 cases which appeared resistant with newer guidelines had a minimum inhibitory concentration (MIC) range between 0.125 and 0.5 µg/ml. MIC50 for the third generation cephalosporins varied between 0.125 and 0.5 µg/ml over 6 years whereas MIC90 varied with a broader range of 0.19-1 µg/ml. The gap between NAR and ciprofloxacin-resistant strains identified using 2011 guidelines has been reduced; however, it remains to be seen whether additional NAS, ciprofloxacin-resistant isolates are truly resistant to ciprofloxacin by other mechanisms of resistance.


Asunto(s)
Antibacterianos/farmacología , Ciprofloxacina/farmacología , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana/normas , Salmonella paratyphi A/efectos de los fármacos , Salmonella typhi/efectos de los fármacos , Hospitales Pediátricos , Humanos , India , Ácido Nalidíxico/farmacología , Estudios Prospectivos , Centros de Atención Terciaria
11.
Indian J Med Microbiol ; 33(2): 305-7, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25865992

RESUMEN

Bordetella trematum spp. nov. has been isolated from wounds, ear infections and diabetic ulcers. We report a case of a 7-month-old infant with fever, vomiting and abnormal body movements with bacteremia caused by this novel species. The infant responded to fluoroquinolone and macrolide combination therapy.


Asunto(s)
Bacteriemia/diagnóstico , Bacteriemia/patología , Infecciones por Bordetella/diagnóstico , Infecciones por Bordetella/patología , Bordetella/clasificación , Bordetella/aislamiento & purificación , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Bacteriemia/microbiología , Infecciones por Bordetella/microbiología , Femenino , Fluoroquinolonas/uso terapéutico , Humanos , Lactante , Macrólidos/uso terapéutico , Pruebas de Sensibilidad Microbiana , Resultado del Tratamiento
12.
Environ Sci Pollut Res Int ; 22(2): 946-62, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25277712

RESUMEN

Nuclear power reactors are operating in 31 countries around the world. Along with reactor operations, activities like mining, fuel fabrication, fuel reprocessing and military operations are the major contributors to the nuclear waste. The presence of a large number of fission products along with multiple oxidation state long-lived radionuclides such as neptunium ((237)Np), plutonium ((239)Pu), americium ((241/243)Am) and curium ((245)Cm) make the waste streams a potential radiological threat to the environment. Commonly high concentrations of cesium ((137)Cs) and strontium ((90)Sr) are found in a nuclear waste. These radionuclides are capable enough to produce potential health threat due to their long half-lives and effortless translocation into the human body. Besides the radionuclides, heavy metal contamination is also a serious issue. Heavy metals occur naturally in the earth crust and in low concentration, are also essential for the metabolism of living beings. Bioaccumulation of these heavy metals causes hazardous effects. These pollutants enter the human body directly via contaminated drinking water or through the food chain. This issue has drawn the attention of scientists throughout the world to device eco-friendly treatments to remediate the soil and water resources. Various physical and chemical treatments are being applied to clean the waste, but these techniques are quite expensive, complicated and comprise various side effects. One of the promising techniques, which has been pursued vigorously to overcome these demerits, is phytoremediation. The process is very effective, eco-friendly, easy and affordable. This technique utilizes the plants and its associated microbes to decontaminate the low and moderately contaminated sites efficiently. Many plant species are successfully used for remediation of contaminated soil and water systems. Remediation of these systems turns into a serious problem due to various anthropogenic activities that have significantly raised the amount of heavy metals and radionuclides in it. Also, these activities are continuously increasing the area of the contaminated sites. In this context, an attempt has been made to review different modes of the phytoremediation and various terrestrial and aquatic plants which are being used to remediate the heavy metals and radionuclide-contaminated soil and aquatic systems. Natural and synthetic enhancers, those hasten the process of metal adsorption/absorption by plants, are also discussed. The article includes 216 references.


Asunto(s)
Biodegradación Ambiental , Metales Pesados , Plantas , Radioisótopos , Contaminantes del Suelo , Contaminantes Químicos del Agua , Organismos Acuáticos , Metales Pesados/química , Metales Pesados/metabolismo , Radioisótopos/química , Radioisótopos/metabolismo , Contaminantes del Suelo/química , Contaminantes del Suelo/metabolismo , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/metabolismo
13.
Rev Sci Instrum ; 86(6): 066101, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26133876

RESUMEN

A sensitive radioactive aerosols sensor has been designed and developed. Its design guidance is based on the need for a low operational cost and reliable measurements to provide daily aerosol monitoring. The exposure of diethylene-glycol bis (allylcarbonate) to radiation causes modification of its physico-chemical properties like surface roughness and reflectance. In the present study, optical sensor based on the reflectance measurement has been developed with an aim to monitor real time presence of alpha radioactive aerosols emitted from thorium nitrate hydrate. The results shows that the fabricated sensor can detect 0.0157 kBq to 0.1572 kBq of radio activity by radioactive aerosols generated from (Th(NO3)4 ⋅ 5H2O) at 0.1 ml/min flow rate. The proposed instrument will be helpful to monitor radioactive aerosols in/around a nuclear facility, building construction sites, mines, and granite polishing factories.

14.
Talanta ; 47(5): 1271-8, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18967433

RESUMEN

Ion-pair extraction behaviour of uranyl ion from aqueous solutions was studied at pH 3.0 employing crown ethers viz. benzo 15 crown 5 (B15C5), 18 crown 6 (18C6), dibenzo 18 crown 6 (DB18C6), and dibenzo 24 crown 8 (DB24C8) in chloroform as the organic phase and picric acid as the organophilic counter anion. The stoichiometry of the extracted species corresponded to [UO(2)(crown ether)(n)](2+).[pic(-)](2) where n=1.5 for benzo 15 crown 5 and 1 for 18 crown 6 as well as dibenzo 18 crown 6. Adducts of DB24C8 could not be observed as practically no extraction was possible using this reagent. The separation behaviour of fission products from an irradiated uranium target was also studied. An interesting observation on the separation of trivalent lanthanides from uranyl ion is reported.

15.
Talanta ; 45(2): 387-95, 1997 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-18967017

RESUMEN

The extraction of strontium from nitric acid medium was investigated employing DCH18C6 in aliphatic alcohols as the diluents. 80% Butanol-20% octanol mixture was found to give higher D(Sr) values as compared to other alcohols investigated. A linear correlation between the organic phase water content and D(Sr) was observed, based on which the extraction mechanism was postulated. Effect of anion, cation, extractant concentration, nitric acid concentration and temperature on D(Sr) was also studied. Conditions for recovery (>90%) were arrived at and selectivity with respect to other interfering fission products was observed with most of the metal ions studied.

16.
Talanta ; 43(8): 1305-12, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18966605

RESUMEN

The extraction behaviour of thorium(IV) from aqueous nitric acid employing 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) in the presence of tri-n-octyl phosphine oxide (TOPO) as well as tri-n-butyl phosphate (TBP) in xylene medium was investigated. The extraction constant (log k(ex)) for the binary organic phase species Th(PBI)(4) was determined to be 8.26 which is by far the largest amongst the corresponding values known for other beta-diketones. The overall extraction constant (log K) for the ternary species Th(PBI)(4) TBP and Th(PBI)(4).2TOPO were estimated to be 14.96 and 20.96 respectively. An inverse correlation of the adduct formation constant (log K(s)) with the pK(a) of the beta-diketones, 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and HPBI, was observed. The steric as well as the electronic effects of adduct formation have been discussed. Analytical application of HPBI for the separation of (234)Th radiotracer from natural uranium (99.3% (238)U) has been suggested.

17.
Burns ; 29(2): 129-32, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12615458

RESUMEN

A retrospective study of bacterial isolates from the wounds of patients admitted to burns unit, was undertaken at Guru Tegh Bahadur Hospital, University College of Medical Sciences, Delhi, India, over a period of 5 years between July 1997 and April 2002. The study compared the results obtained with the previous 5 years data (June 1993-June 1997) from the same unit to determine the changing patterns and emerging trends of bacterial isolates and their antimicrobial susceptibilities. Pseudomonas species (31%) and Staphylococcus aureus (22%) were the most common pathogens followed by Klebsiella species (19%). Multi-drug resistant (MDR) Acinetobacter species (9%) have emerged as an important nosocomial pathogen in our burn unit. Most of the gram-negative isolates obtained were found to be multi-drug resistant and 61% of the tested isolates were extended spectrum beta-lactamase (ESBL) producers. Concomitant resistance to penicillin and aminoglycosides was observed in 61% of Enterococcus fecalis isolates. When compared with the results of previous 5 years (June 1993-June 1997) Pseudomonas spp. was still the commonest pathogen in the burns unit. However, isolation of this organism and other gram-negative organisms has decreased in comparison to previous years. The incidence of antimicrobial resistance has markedly increased over the past years resulting in limitation of therapeutic options.


Asunto(s)
Quemaduras/microbiología , Infección de Heridas/microbiología , Unidades de Quemados/tendencias , Infección Hospitalaria/microbiología , Resistencia a Medicamentos , Farmacorresistencia Bacteriana Múltiple , Humanos , India , Pruebas de Sensibilidad Microbiana/métodos , Resistencia a las Penicilinas , Estudios Retrospectivos , Infección de Heridas/tratamiento farmacológico
18.
Appl Radiat Isot ; 60(5): 621-4, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15082037

RESUMEN

The sorption and desorption behaviour of several radionuclides, including 241Am, 152,154Eu, 233U, 137Cs, 90Sr and 90Y was studied under varying acidities using zirconium vanadate as ion exchanger. The sorption follows the order: Cs > Eu > Am >Y > U, while Sr was not taken up by the ion exchanger. A radiochemical separation scheme for the 90Y daughter from its 90Sr parent using zirconium vanadate ion exchanger has been developed. The exchanger was synthesized and characterized in our laboratory.

19.
Indian J Med Microbiol ; 31(3): 237-41, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23883708

RESUMEN

PURPOSE: Carbapenem resistance in Acinetobacter baumannii has become highly rampant, which has been ascribed to the presence of multiple carbapenemases. The objective of the present study was to prospectively investigate the presence of multiple carbapenemase encoding genes in clinical isolates of A. baumannii. MATERIALS AND METHODS: A total of 30 imipenem resistant, consecutive non-repeat clinical isolates A. baumannii from a Tertiary Care Centre of Delhi were subjected to antimicrobial susceptibility testing (AST), screening for carbapenemase production by modified Hodge test (MHT) and determination of minimum inhibitory concentration for imipenem by E-Test® . These were subjected to Real time PCR for blaIMP-1 and 2 , blaVIM-1 and 2, blaOXA23, 24, 51 and 58 using SYBR green-I. These were grouped together on the basis of their genotype as each isolate harboured multiple carbapenemases and correlated with their AST profile. Detection of the novel carbapenemase blaNDM-1 was performed by real time PCR using TaqMan probes on 14 isolates. RESULTS: Colistin appeared to be the most effective drug in vitro, followed by tetracycline and beta lactam/beta lactamase inhibitor combinations. All, but one isolate were positive for the MHT. All 30 isolates were positive for blaOXA-51 like gene as well as blaIMP-1 and blaVIM-1 genes. blaOXA 24 and 58 were not detected in any of the isolates. blaIMP-2 , blaVIM-2 , blaOXA-23 were present in 15, 6 and 14 isolates respectively. Grouping based on the genotypic profile did not correlate with susceptibility pattern. Nine among the 14 isolates also harboured the novel blaNDM-1 gene. CONCLUSIONS: This is the first study from North India, which comprehensively detected the presence of multiple carbapenemases as well the blaNDM-1 gene. The presence of the novel gene blaNDM-1 indicated ability of A. baumannii to acquire new carbapenemase genes despite the existence of multiple carbapenemase genes. The present study confirmed the presence of multiple genetic mechanisms for carbapenemases production among the clinical isolates of A. baumannii in north India.


Asunto(s)
Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/enzimología , Acinetobacter baumannii/genética , Antibacterianos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Carbapenémicos/metabolismo , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , Acinetobacter baumannii/aislamiento & purificación , Genotipo , Humanos , Hidrólisis , India , Pruebas de Sensibilidad Microbiana , Estudios Prospectivos , Reacción en Cadena en Tiempo Real de la Polimerasa
20.
J Colloid Interface Sci ; 393: 347-51, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23190796

RESUMEN

The two long alkyl chain derivatives of diglycolamide (DGA), viz. N,N,N',N'-tetraoctyl diglycolamide (TODGA) and N,N,N',N'-tetra(2-ethylhexyl)-diglycolamide (T2EHDGA) have been found promising for actinide partitioning from high-level waste. The solvent extraction studies have suggested the participation of three to four DGA molecules in the extracted complex of trivalent actinides and lanthanides. However, coordination of 3-4 tridentate DGA ligands with trivalent f-elements seems to be unusual due to restricted coordination sites in these metal ions. Nonetheless, the extraction data have been explained in view of the formation of aggregates of these ligands in the organic phase. Small Angle Neutron Scattering (SANS) measurements were carried out to investigate the aggregation behavior of DGA ligands in deuterated n-dodecane. The aggregation of DGA molecules was facilitated by the presence of acid. However, the presence of nitrate ions in the aqueous phase had no significant effect on the aggregation of DGA. Similarly, the presence of metal ions such as Sr(II) or Eu(III) marginally affected the aggregation tendency of DGA molecules. TODGA displayed higher aggregation tendency than that of T2EHDGA. The extraction data of trivalent f-elements were in conformity with the aggregation tendency of the two DGA ligands.


Asunto(s)
Glicolatos/química , Alcanos/química , Glicolatos/síntesis química , Glicolatos/aislamiento & purificación , Estructura Molecular , Dispersión del Ángulo Pequeño , Difracción de Rayos X
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA