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1.
Phys Rev Lett ; 128(25): 252002, 2022 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-35802440

RESUMEN

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

3.
J Geriatr Oncol ; 13(6): 892-903, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35292232

RESUMEN

BACKGROUND: Cancer survivors over the age of 65 have unique needs due to the higher prevalence of functional and cognitive impairment, comorbidities, geriatric syndromes, and greater need for social support after chemotherapy. In this study, we will evaluate whether a Geriatric Evaluation and Management-Survivorship (GEMS) intervention improves functional outcomes important to older cancer survivors following chemotherapy. METHODS: A cluster-randomized trial will be conducted in approximately 30 community oncology practices affiliated with the University of Rochester Cancer Center (URCC) National Cancer Institute Community Oncology Research Program (NCORP) Research Base. Participating sites will be randomized to the GEMS intervention, which includes Advanced Practice Practitioner (APP)-directed geriatric evaluation and management (GEM), and Survivorship Health Education (SHE) that is combined with Exercise for Cancer Patients (EXCAP©®), or usual care. Cancer survivors will be recruited from community oncology practices (of participating oncology physicians and APPs) after the enrolled clinicians have consented and completed a baseline survey. We will enroll 780 cancer survivors aged 65 years and older who have completed curative-intent chemotherapy for a solid tumor malignancy within four weeks of study enrollment. Cancer survivors will be asked to choose one caregiver to also participate for a total up to 780 caregivers. The primary aim is to compare the effectiveness of GEMS for improving patient-reported physical function at six months. The secondary aim is to compare effectiveness of GEMS for improving patient-reported cognitive function at six months. Tertiary aims include comparing the effectiveness of GEMS for improving: 1) Patient-reported physical function at twelve months; 2) objectively assessed physical function at six and twelve months; and 3) patient-reported cognitive function at twelve months and objectively assessed cognitive function at six and twelve months. Exploratory health care aims include: 1) Survivor satisfaction with care, 2) APP communication with primary care physicians (PCPs), 3) completion of referral appointments, and 4) hospitalizations at six and twelve months. Exploratory caregiver aims include: 1) Caregiver distress; 2) caregiver quality of life; 3) caregiver burden; and 4) satisfaction with patient care at six and twelve months. DISCUSSION: If successful, GEMS would be an option for a standardized APP-led survivorship care intervention. TRIAL REGISTRATION: ClinicalTrials.govNCT05006482, registered on August 9, 2021.


Asunto(s)
Supervivientes de Cáncer , Neoplasias , Anciano , Cuidadores/psicología , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/psicología , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Sobrevivientes/psicología , Supervivencia
4.
Phys Rev Lett ; 127(15): 152301, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34678020

RESUMEN

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.60) and Q^{2} (3.1 to 8.4 GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, and dσ_{LT^{'}}/dt are extracted as a function of the proton momentum transfer t-t_{min}. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

5.
Nature ; 590(7847): 561-565, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33627814

RESUMEN

The fundamental building blocks of the proton-quarks and gluons-have been known for decades. However, we still have an incomplete theoretical and experimental understanding of how these particles and their dynamics give rise to the quantum bound state of the proton and its physical properties, such as its spin1. The two up quarks and the single down quark that comprise the proton in the simplest picture account only for a few per cent of the proton mass, the bulk of which is in the form of quark kinetic and potential energy and gluon energy from the strong force2. An essential feature of this force, as described by quantum chromodynamics, is its ability to create matter-antimatter quark pairs inside the proton that exist only for a very short time. Their fleeting existence makes the antimatter quarks within protons difficult to study, but their existence is discernible in reactions in which a matter-antimatter quark pair annihilates. In this picture of quark-antiquark creation by the strong force, the probability distributions as a function of momentum for the presence of up and down antimatter quarks should be nearly identical, given that their masses are very similar and small compared to the mass of the proton3. Here we provide evidence from muon pair production measurements that these distributions are considerably different, with more abundant down antimatter quarks than up antimatter quarks over a wide range of momenta. These results are expected to revive interest in several proposed mechanisms for the origin of this antimatter asymmetry in the proton that had been disfavoured by previous results4, and point to future measurements that can distinguish between these mechanisms.

6.
Sci Rep ; 9(1): 20372, 2019 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-31889136

RESUMEN

Adaptive fluoride ceramic with glass forming layer (GCZBL-Er) used in laser anti-escaping has been prepared by one-step synthesis, and the thickness of glass layer is identified as ~0.41 mm. Blue, green and red emissions of Er3+/Yb3+ codoped fluoride ceramic (CZBL-Er) and glass layer (GZBL-Er) have been investigated under ~980 nm laser pumping. With the forming of thin glass layer on ceramic surface, the absorption intensities on diffuse reflection of GCZBL-Er at 974 nm and 1.53 µm increase by 48% and 53% than those of CZBL-Er. Excited by a 979 nm laser, the presence of the glass layer increases the absolute absorption rate in spectral power from 75% in CZBL-Er to 83% in GCZBL-Er, which is consistent with the improvement in the absorbed photon number. In addition, the quantum yield of GCZBL-Er complex is raised by 28.4% compared to the case of ceramic substrate by photon quantification. Intense absorption-conversion ability and efficient macroscopical anti-escaping effect confirm the superiority of ingenious structure in the fluoride ceramics with glass forming layer, which provides a new approach for developing the absorption-conversion materials of anti-NIR laser detection.

7.
Phys Rev Lett ; 116(23): 232001, 2016 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-27341225

RESUMEN

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1 GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

8.
Eye (Lond) ; 27(3): 418-24, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23288141

RESUMEN

PURPOSE: This study was conducted to examine the atropine eye drop prescription trend for children diagnosed with myopia, and to determine the factors associated with the prescription of atropine eye drops. DESIGN: This was a population-based cross-sectional study. METHODS: This study was conducted using a national representative sample from the National Health Insurance (NHI) claims data. All school children between 4 and 18 years of age who had visited an ophthalmologist and were diagnosed with myopia between 2000 and 2007 were included herein. The main outcome measure was the proportion of subjects who were prescribed atropine eye drops in each year. Logistic regression was used to identify the factors associated with atropine eye drops being prescribed. RESULTS: The prescription of atropine eye drops for children diagnosed with myopia increased significantly from the school years 2000 (36.9%) to 2007 (49.5%). There was also a shift from prescribing high concentrations (0.5 and 1%) of atropine eye drops to lower concentration ones (0.3, 0.25, and 0.1%) within this period. Atropine eye drops were more frequently prescribed to 9-12-year-old children (OR=1.26-1.42, compared with those 7-8 years old), and to children from families with a high socioeconomic status (OR=1.19-1.25); however, they were less prescribed to those living in mid to low urbanized areas (OR=0.65-0.84). CONCLUSIONS: This study revealed an increasing trend of atropine eye drop prescription for children with myopia in Taiwan. Our study provides eye-care professionals worldwide a reference for the potential integration of atropine eye drops into their clinical practice toward children with myopia.


Asunto(s)
Atropina/administración & dosificación , Prescripciones de Medicamentos/estadística & datos numéricos , Midriáticos/administración & dosificación , Miopía/tratamiento farmacológico , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adolescente , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Masculino , Miopía/epidemiología , Programas Nacionales de Salud/estadística & datos numéricos , Soluciones Oftálmicas , Oftalmología , Clase Social , Taiwán/epidemiología , Población Urbana/estadística & datos numéricos
9.
Br J Dermatol ; 164(1): 47-53, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20854438

RESUMEN

BACKGROUND: Mal de Meleda (MDM) is palmoplantar erythrokeratoderma with an autosomal recessive inheritance and is caused by a mutation in the gene encoding SLURP-1 (lymphocyte antigen 6/urokinase-type plasminogen activator receptor related protein-1). SLURP-1 is an allosteric agonist to the nicotinic acetylcholine receptor (nAchR) and it regulates epidermal homeostasis. In addition, murine studies have shown that nAchR signalling is important for the regulation of T-cell function. Among the family members, patients with the homozygous SLURP1 (previously known as ARS component B) mutation are prone to melanoma and viral infection, which might link to defective T-cell function as well as a derangement of epidermal homeostasis. OBJECTIVES: To investigate the association of the SLURP1 gene mutation with T-cell activation in a Taiwanese family with MDM. To test that SLURP-1 is essential for T-cell activation. METHODS: Human peripheral blood mononuclear cells (PBMCs) were isolated from a Taiwanese MDM family bearing the G to A substitution in nucleotide 256 in the SLURP1 gene, corresponding to a glycine to arginine substitution at amino acid 86 (G86R) in the SLURP-1 protein. PBMCs from homozygotes and wild-type controls were stimulated with anti-CD3/anti-CD28 antibodies and the level of T-cell activation was determined by the stimulation index. RESULTS: PBMCs with the heterozygous and homozygous SLURP-1 G86R mutation had defective T-cell activation. This was restored by the addition of 0·5 µg mL(-1) recombinant human SLURP-1 protein. CONCLUSIONS: Patients with MDM with the homozygous SLURP-1 G86R mutation may have an impaired T-cell activation. The presence of wild-type SLURP-1 is essential for normal T-cell activation.


Asunto(s)
Antígenos Ly/genética , Activación de Linfocitos/genética , Mutación Puntual/genética , Linfocitos T/inmunología , Activador de Plasminógeno de Tipo Uroquinasa/genética , Anciano , Pueblo Asiatico/genética , Western Blotting , Antígenos CD28/sangre , Complejo CD3/sangre , Femenino , Humanos , Queratodermia Palmoplantar/complicaciones , Queratodermia Palmoplantar/genética , Queratodermia Palmoplantar/inmunología , Lentigo/complicaciones , Lentigo/patología , Leucocitos Mononucleares/inmunología , Masculino , Melanoma/complicaciones , Melanoma/patología , Reacción en Cadena de la Polimerasa , Taiwán , Verrugas/complicaciones , Verrugas/patología
10.
Biotechnol Bioeng ; 99(2): 341-50, 2008 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-17625790

RESUMEN

Numerous biotechnological production processes are based on the submerse cultivation of filamentous fungi. Process design, however, is often hampered by the complex growth pattern of these organisms. In the morphologic development of coagulating filamentous fungi, like Aspergillus niger, conidial aggregation is the first step of filamentous morphogenesis. For a proper description of this phenomenon it is necessary to characterize conidial populations. Kinetic studies performed with an in-line particle size analyzer suggested that two distinct aggregation steps have to be considered. The first step of conidial aggregation starts immediately after inoculation. Both the rate constants of formation and disintegration of aggregates have been determined by measuring the concentration of conidia at the beginning of the cultivation and the concentration of particles at steady state during the first hours of cultivation. In contrast to the first aggregation step, where the collision of conidia is presumed to be responsible for the process, the second aggregation step is thought to be initiated by germination of conidia. Growing hyphae provide additional surface for the attachment of non- germinated conidia, which leads to a strong decrease in particle concentration. The specific hyphal length growth rate and the ratio of particle concentration to the growing adhesion hyphal surface are decisive matters of the second aggregation step. Both aggregation steps can be described by population dynamics and simulated using the program package PARSIVAL (PARticle SIze eVALution) for the treatment of general particle population balances.


Asunto(s)
Aspergillus niger/fisiología , Esporas Fúngicas/metabolismo , Reactores Biológicos/microbiología , Hifa/fisiología , Microbiología Industrial/métodos , Modelos Biológicos
11.
Int J Clin Pract ; 61(4): 589-93, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16749915

RESUMEN

Extra-corporeal life support (ECLS) has been applied successfully to congenital respiratory defects but less optimally to acquired pulmonary failure. We extended this support to certain extreme complexities of patients with acute respiratory distress. From January 2003 to June 2005, 16 (nine men and seven women) patients refractory to ventilator support were treated with ECLS. Their median age was 32.4 years (1.5-70). The triggering events were pulmonary haemorrhage (n = 4), pneumonia (n = 7), aspiration (n = 2) and pancreatitis (n = 3). The indications for support were hypoxaemia in 13 and hypercapnia in three patients. Ten (63%) met the criteria of fast entry. Thirteen (81%) received veno-venous (V-V) mode support and the other three received veno-arterial mode support initially, but then converted to V-V mode after sufficient oxygenation stabilised haemodynamics. Initial pump flow was maximised to improve (mean 3250 +/- 1615 ml/min) to improve the oxygenation. Four patients with active pulmonary haemorrhage were heparin free in the first 12-24 h of support without complications. Excluding one prematurely terminated patient because of brain permanent damage, the duration of support was 162 +/- 95 h (67-363). Eleven (69%) weaned successfully from ECLS and 10 (63%) discharged and regained normal pulmonary performance in a median of 26.8 months follow-up. Pulmonary support using ECLS was feasible in selected patients with acute respiratory distress. Modification of guidelines for liberal use, early deployment before secondary organ damage and prevention of complications during support were the key to final success.


Asunto(s)
Oxigenación por Membrana Extracorpórea/métodos , Síndrome de Dificultad Respiratoria/terapia , Adolescente , Adulto , Anciano , Algoritmos , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Selección de Paciente , Síndrome de Dificultad Respiratoria/etiología , Resultado del Tratamiento , Desconexión del Ventilador/métodos
13.
J Thromb Haemost ; 2(4): 597-604, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15102014

RESUMEN

A mutation (W501S) in the vitamin K-dependent gamma-glutamyl carboxylase (VKC) that leads to a congenital bleeding disorder was recently discovered in two patients. To characterize the enzyme defect, recombinant VKC-W501S was expressed in and purified from insect cells. The major effect of the mutation appears to be to decrease the affinity of the carboxylase for the propeptide of its substrates. This observation agrees with recent data that place part of the propeptide binding site within residues 495-513 of VKC. Additionally, we demonstrate that the affinity between descarboxy osteocalcin (d-OC) and VKC remains unaffected by the W501S mutation. This confirms earlier data that the high-affinity site for d-OC is not located on the propeptide binding domain of VKC. Two properties of the enzyme suggest an explanation for the observation that vitamin K supplementation ameliorates the effects of the mutation: (i) since full carboxylation requires the propeptide to remain bound to the enzyme sufficiently long for full carboxylation, a reduced affinity can cause its premature release before carboxylation is complete; (ii) propeptide binding results in a decrease of the KM for vitamin K hydroquinone in wild-type, but not in mutant carboxylase, resulting in increased vitamin K requirement of affected subjects.


Asunto(s)
Ligasas de Carbono-Carbono/genética , Ligasas de Carbono-Carbono/metabolismo , Mutación Missense , Animales , Sitios de Unión , Dióxido de Carbono/metabolismo , Línea Celular , Clonación Molecular , Factor IX/metabolismo , Humanos , Cinética , Osteocalcina/metabolismo , Proteínas Recombinantes , Spodoptera
14.
Transplant Proc ; 35(8): 3139-41, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14697998

RESUMEN

Cyclosporine (CsA), a calcineurin inhibitor, has been associated with endothelial dysfunction in transplant patients. Human and in vitro studies suggest that CsA produces endothelial dysfunction by impairing vascular endothelium-dependent relaxation. However, little is know about the CsA effects to modulate the vasorelaxation after prolonged graft preservation. In this study using a protocol designed to eliminate the influences of infusion pressure and shear stress, we evaluated the effect of CsA on vasorelaxation of coronary and pulmonary arteries after 16-hour University of Wisconsin (UW) solution preservation.


Asunto(s)
Adenosina , Alopurinol , Vasos Coronarios/fisiología , Ciclosporina/farmacología , Glutatión , Insulina , Preservación de Órganos/métodos , Arteria Pulmonar/fisiología , Rafinosa , Vasodilatación/fisiología , Animales , Vasos Coronarios/efectos de los fármacos , Perros , Modelos Animales , Soluciones Preservantes de Órganos , Arteria Pulmonar/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología
15.
J Thromb Haemost ; 1(1): 118-23, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12871548

RESUMEN

We report the identification of a gene capable of encoding a novel Gla (gamma-carboxyglutamic acid) protein from the tunicate Halocynthia roretzi, a primitive member of the phylum Chordata. We call this new hypothetical protein Gla-RTK; it has a Gla domain typical of human vitamin K-dependent coagulation factors, a transmembrane domain, and a receptor tyrosine kinase domain. The receptor tyrosine kinase domain is very similar to the ARK (adhesion-related kinase) family of receptor tyrosine kinases. The ARK family includes Axl, Tyro3, and c-Mer. This gene also encodes a propeptide that binds to the human gamma-glutamyl carboxylase within a range of affinities observed for mammalian propeptides. The cDNA for this putative protein is found distributed throughout the oocyte and embryo but the cDNA is apparently not transcribed except during oogenesis. One of the most interesting aspects of this hypothetical protein is that its Gla domain is highly homologous to the Gla domain of Gas6, a ligand for Axl, while its receptor tyrosine kinase domain is highly homologous to Axl.


Asunto(s)
Ácido 1-Carboxiglutámico/genética , Proteínas Tirosina Quinasas Receptoras/genética , Ácido 1-Carboxiglutámico/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Factores de Coagulación Sanguínea/química , Factores de Coagulación Sanguínea/metabolismo , ADN Complementario/genética , Hibridación in Situ , Datos de Secuencia Molecular , Oogénesis/fisiología , Péptidos/genética , Péptidos/metabolismo , Estructura Terciaria de Proteína , Proteínas Tirosina Quinasas Receptoras/química , Proteínas Tirosina Quinasas Receptoras/metabolismo , Homología de Secuencia de Aminoácido , Distribución Tisular , Transcripción Genética , Urocordados/química , Urocordados/genética , Vitamina K/metabolismo
16.
Surg Endosc ; 16(11): 1612-4, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12085131

RESUMEN

BACKGROUND: Empyema frequently complicates the hospitalization of children; and in advanced stages, it often requires surgical intervention. In this study, we investigated the use of video-assisted thoracic surgery (VATS) for the management of postpneumonic empyema in children who have had an unsatisfactory medical response. METHODS: We did a retrospective review of the medical records of 51 consecutive patients with loculated empyema (mean age, 5 years; range, 2 months to 15 years) hospitalized at Chang Gung Memorial Hospital between 1995 and 2000. All patients underwent debridement of the necrotic lung tissue and evacuation of the loculated empyema cavity using a VATS approach. RESULTS: The mean operating time for the 51 patients was 90 min (range, 50-210); mean blood loss was 70 cc. Fever subsided within 72 h postoperatively in all patients. On average, chest tubing was removed on the 7th postoperative day (range, 4-18 days). However, in one patient who suffered from a prolonged air leak, the chest tube was not removed until day 18. The mean postoperative stay for all patients was 13.7 days (range, 9-23). No deaths occurred, and all of the children made a good recovery. A follow-up revealed that one of the 51 children patient suffered a left upper lung abscess 7 months after discharge. Left upper lobectomy was performed in this case, and the patient was discharged uneventfully 10 days after the operation. CONCLUSIONS: VATS is a safe and effective treatment for pediatric empyema. Thoracoscopic-assisted surgery facilitates visualization, evacuation, and debridement of the necrotizing lung tissue. Early surgical intervention can avoid lengthy hospitalization and prolonged intravenous antibiotic therapy, and it can accelerate clinical recovery.


Asunto(s)
Empiema Pleural/etiología , Empiema Pleural/cirugía , Neumonía Bacteriana/complicaciones , Cirugía Torácica Asistida por Video/métodos , Adolescente , Pérdida de Sangre Quirúrgica , Niño , Preescolar , Empiema Pleural/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Humanos , Lactante , Tiempo de Internación , Absceso Pulmonar/etiología , Masculino , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Factores de Tiempo , Insuficiencia del Tratamiento
17.
Ann Thorac Surg ; 72(5): 1754-5, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11722088

RESUMEN

Esophageal hemangioma is a rare tumor. This report describes the case of a 69-year-old woman with an esophageal tumor at the middle portion of the esophagus. The patient was successfully treated with minimal access thoracic surgery, and at the 6 month follow-up, the patient was free of any symptoms or recurrence.


Asunto(s)
Neoplasias Esofágicas/cirugía , Hemangioma/cirugía , Anciano , Femenino , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Procedimientos Quirúrgicos Torácicos/métodos
18.
Chang Gung Med J ; 24(7): 451-4, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11565252

RESUMEN

How to optimally treat deep sternal wound infection after open wound infection remains controversial. Biomaterial advances have made local antibiotics-releasing systems a promising alternative for treating deep sternal wound infection. Two patients with deep sternal wound complications were treated with radical wound debridement, sternal refixation, retrosternal suction drainage, bilateral pectoralis major muscle flaps and placement of collagenous drug carriers loaded with vancomycin underneath, above and between the sternal edges. No treatment failure and death occurred in these patients. There were no side effects, treatment failures or deaths after adjuvant treatment with collagenous vancomycin. Preliminary results of these 2 case studies demonstrate the feasibility of successfully treating deep sternal wound infections with collagenous vancomycin in combination with surgical debridement. This technique is easily performed, reliable and safe.


Asunto(s)
Antibacterianos/administración & dosificación , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Colágeno/administración & dosificación , Esternón/cirugía , Infección de la Herida Quirúrgica/tratamiento farmacológico , Vancomicina/administración & dosificación , Anciano , Portadores de Fármacos , Humanos , Masculino , Persona de Mediana Edad
19.
Water Res ; 35(12): 2841-50, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11471684

RESUMEN

A Pseudomonas luteola strain expressing azoreductase activity was utilized to remove the color of an azo dye (reactive red 22) from contaminated solutions. The effects of substrate concentrations, medium compositions, and operation parameters (e.g., pH, temperature, dissolved oxygen, etc.) on decolorization of the azo dye by a P. luteola strain were systematically investigated to reveal the key factors that dominate the performance of azo-dye decolorization. The metabolites resulting from bacterial decolorization were analyzed by high-performance liquid chromatography (HPLC) and mass spectrometery (MS). The results show that the dissolved oxygen and glucose concentration retarded decolorization of reactive red 22 by P. luteola. The optimal azo-dye decolorization occurred at 37 degrees C, while more rapid decolorization took place over pH 7-9. Yeast extract and tryptone strongly enhanced the decolorization. The Michaelis-Menten model can satisfactorily describe the dependence of specific decolorization rate on the concentration of substrate (reactive red 22 or yeast extract). Decolorization of the azo dye by intact cells of P. luteola was essentially independent of the growth phase, whereas the azoreductase activity of the cell-free extract decreased in the order of late-stationary phase > early-stationary phase > mid-log phase. This suggests that mass transfer of the azo dye across the cell membrane may be the rate-limiting step. The HPLC and MS analyses suggest that both partial reduction and complete cleavage of the azo bond could contribute to decolorization of reactive red 22 by P. luteola.


Asunto(s)
Compuestos Azo/metabolismo , Colorantes/metabolismo , NADH NADPH Oxidorreductasas/metabolismo , Pseudomonas/enzimología , Microbiología del Agua , Compuestos Azo/química , Biodegradación Ambiental , Color , Colorantes/química , Concentración de Iones de Hidrógeno , Residuos Industriales/análisis , Modelos Químicos , Nitrorreductasas , Oxígeno/metabolismo , Pseudomonas/aislamiento & purificación , Solubilidad , Temperatura , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/prevención & control , Purificación del Agua/métodos
20.
Catheter Cardiovasc Interv ; 52(1): 67-72, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11146526

RESUMEN

This article reports the status of a new cardiovascular fluoroscopy benchmarking phantom. A joint working group of the Society for Cardiac Angiography and Interventions (SCA&I) and the National Electrical Manufacturers Association (NEMA) developed the phantom. The device was adopted as NEMA standard XR 21-2000, "Characteristics of and Test Procedures for a Phantom to Benchmark Cardiac Fluoroscopic and Photographic Performance," in August 2000. The test ensemble includes imaging field geometry, spatial resolution, low-contrast iodine detectability, working thickness range, visibility of moving targets, and phantom entrance dose. The phantom tests systems under conditions simulating normal clinical use for fluoroscopically guided invasive and interventional procedures. Test procedures rely on trained human observers.


Asunto(s)
Cateterismo Cardíaco/instrumentación , Fluoroscopía/instrumentación , Fluoroscopía/normas , Fantasmas de Imagen , Benchmarking , Cateterismo Cardíaco/métodos , Diseño de Equipo , Seguridad de Equipos , Humanos , Sensibilidad y Especificidad
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