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1.
Rev Sci Instrum ; 94(5)2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37184347

RESUMEN

We report on progress implementing and testing cryogenically cooled platforms for Magnetized Liner Inertial Fusion (MagLIF) experiments. Two cryogenically cooled experimental platforms were developed: an integrated platform fielded on the Z pulsed power generator that combines magnetization, laser preheat, and pulsed-power-driven fuel compression and a laser-only platform in a separate chamber that enables measurements of the laser preheat energy using shadowgraphy measurements. The laser-only experiments suggest that ∼89% ± 10% of the incident energy is coupled to the fuel in cooled targets across the energy range tested, significantly higher than previous warm experiments that achieved at most 67% coupling and in line with simulation predictions. The laser preheat configuration was applied to a cryogenically cooled integrated experiment that used a novel cryostat configuration that cooled the MagLIF liner from both ends. The integrated experiment, z3576, coupled 2.32 ± 0.25 kJ preheat energy to the fuel, the highest to-date, demonstrated excellent temperature control and nominal current delivery, and produced one of the highest pressure stagnations as determined by a Bayesian analysis of the data.

3.
Rev Sci Instrum ; 92(7): 073505, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-34340419

RESUMEN

A deuterium-ice extruder has been developed for inertial confinement fusion experiments on the Sandia National Laboratories Z Facility. The screw-driven extruder is filled via desublimation, where a slow flow of deuterium gas enters the extruder cavity and freezes to the walls without entering the liquid phase. Ice generated in this manner is optically clear, demonstrating its high uniformity. When the extruder cavity is filled with ice, the screw is driven downward, closing off the gas-fill line. With the ice cavity isolated, further screw rotation compresses the deuterium through a nozzle, extruding a fiber. Fiber diameters ranging from 200 to 500 µm have been extruded to lengths of 1.5 feet before hitting the vacuum chamber floor. The fiber straightness improves with the nozzle length-to-diameter aspect ratio. Deuterium-ice fibers can persist in high vacuum for more than 10 min before breaking free from the nozzle. The peripheral infrastructure required for Z experimental operations is under development. An in-vacuum stepper-motor-based drive system will allow remote operation, and a translating cathode will ensure proper placement of the fiber in the powerflow hardware.

4.
Trop Biomed ; 31(2): 347-50, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25134904

RESUMEN

American trypanosomiasis (Chagas disease) caused by the protozoan parasite Trypanosoma cruzi is endemic to parts of South America and the Caribbean. Infected dogs are important in the epidemiology of the parasite as they can play a role in the transmission of the parasite to humans. A total of 399 dog sera (242 stray and 157 pet dogs) were examined for T. cruzi infection; using a qualitative immunochromatographic dipstick test, based on recombinant antigens specific for American trypanosomiasis (Trypanosoma detect rapid test; InBios international, Inc., Seattle, Washington). Overall seroprevalence for T. cruzi was estimated at 10.5% (95% confidence interval: 7.5% to 13.5%); with stray dogs being significantly more affected (p<0.05, χ2). Results from this study indicate that dogs in Grenada are moderately exposed to T. cruzi compared to other areas in the region.


Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Enfermedad de Chagas/veterinaria , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/parasitología , Trypanosoma cruzi/inmunología , Animales , Antígenos de Protozoos , Enfermedad de Chagas/epidemiología , Cromatografía de Afinidad , Perros , Grenada/epidemiología , Estudios Seroepidemiológicos
5.
Neurology ; 69(17): 1665-71, 2007 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-17898327

RESUMEN

BACKGROUND: Guillain-Barré syndrome (GBS) is an acute, immune-mediated flaccid paralysis frequently associated with Campylobacter infection. Of two predominant GBS subtypes, a demyelinating subtype (acute inflammatory demyelinative polyneuropathy [AIDP]) predominates in the United States and Europe, and axonal subtype (acute motor axonal neuropathy [AMAN]) is the predominant form in China. Previous clinical studies suggested that AMAN also occurs in Mexican children. The purpose of this study was to describe the subtypes of GBS in children from Mexico City. METHODS: We prospectively studied 121 children admitted to two pediatric hospitals in Mexico City from 1996 to 2002. Clinical histories were obtained, electrophysiologic studies were performed to determine GBS subtype, and microbiologic studies were performed. RESULTS: Of the 121 children, 46 had AMAN and 32 had AIDP. The male to female ratio was 1.3 for AMAN cases (mean age = 6.3) and 3.0 for AIDP cases (mean age = 7.0). There was a strong seasonal distribution of AMAN cases in July to September. Children with AMAN, but not AIDP, had worsening of illness during hospitalization as judged by peak severity scores. Vomiting was more likely in AIDP (28.1%) vs AMAN (6.5%) (p = 0.012) and diarrhea was more common in AMAN (32.6%) than AIDP (12.5%) (p = 0.06). IgG anti-GM1 antibody titers were higher in patients with AMAN vs AIDP (p = 0.067). Anti-GD1a antibodies were equally present in both groups. Anti GQ1b titers were higher in AMAN vs AIDP (p = 0.009). Campylobacter antibody responses were positive in 44.1% of patients with AMAN and 37.0% of patients with AIDP. Twenty patients (14 = AMAN, 6 = AIDP) had positive stool cultures for C jejuni. Two serotypes, HS:19 and HS:41, accounted for 6 of 10 Campylobacter isolates available for serotyping from these cases. CONCLUSIONS: This study confirms that acute motor axonal neuropathy is an important Guillain-Barré syndrome subtype in Mexican children, is associated with diarrhea, and occurs seasonally.


Asunto(s)
Síndrome de Guillain-Barré/epidemiología , Síndrome de Guillain-Barré/fisiopatología , Adolescente , Infecciones por Campylobacter/epidemiología , Niño , Preescolar , Diarrea/etiología , Femenino , Gangliósido G(M1)/análogos & derivados , Gangliósido G(M1)/inmunología , Síndrome de Guillain-Barré/microbiología , Humanos , Inmunoglobulina G/sangre , Lactante , Masculino , México/epidemiología , Neuronas Motoras/patología , Estaciones del Año
6.
Ginecol Obstet Mex ; 69: 65-71, 2001 Feb.
Artículo en Español | MEDLINE | ID: mdl-11339176

RESUMEN

OBJECTIVE: Evaluate the prognostic value of the early response of the serum estradiol FSH y LH action of leuprolide acetate during the folicular phase, used as an adjuvant to ovarian stimulation in IVF-ET. STUDY DESIGN: Were analyzed 31 cycles of stimulation in 26 patients with sterility primary and secondary. Where measured estradiol, FSH, LH on cycle day 2 to 5 for to establish the patterns of response to GnRHa administration. Were compared the response patterns in relation to the number of oocyte captured, estradiol in the day of application of hCG, number of embryos and fertilization rate using (t-student, wilcoxon test and X2). RESULTS: Where observed four distincts patterns of response of estradiol. Pattern A: 133 cycles, presented a prompt elevation of estradiol, followed by a fall on the 4th cycle's day. Pattern B: 9 cycles delayed elevation of the estradiol, followed by a fall on the 6th cycles day. Pattern C: 7 cycles showed persistent elevation of the estradiol. Pattern D: 2 cycles no response of the estradiol (canceled cycles). Was found a significative difference in the estradiol level the day of application of hCG, number of captured oocytes and number of embrions in the pattern A in relation with B and C. No significative difference were found in the fertilization rate. The seric level of FSH and LH were no predictives. We concluded that the response pattern of the estradiol to the leuprolide acetate is the good prognosis indicator of the results of IVF-ET.


Asunto(s)
Estradiol/sangre , Hormona Folículo Estimulante/sangre , Leuprolida/uso terapéutico , Hormona Luteinizante/sangre , Inducción de la Ovulación/métodos , Adulto , Transferencia de Embrión , Femenino , Fertilización In Vitro , Humanos , Pronóstico , Factores de Tiempo
7.
Equine Vet J ; 32(3): 247-52, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10836481

RESUMEN

Faecal specimens from 305 horses and mules used as packstock at one of 17 commercial or governmental (National Park Service, US Forest Service) operations were examined for Giardia duodenalis and Cryptosporidium parvum using immunofluorescent microscopy. Fourteen packstock (4.6%) were shedding G. duodenalis cysts, with herd-level prevalences ranging 0-22%. Number of packstock in the corral, size of corral and density of packstock in the corral were associated with the odds of shedding G. duodenalis cysts. None of the horses had detectable C. parvum oocysts. Assuming a sensitivity of at least 43% and a specificity of 100% for our assay, the estimated maximum true prevalence of shedding of C. parvum for packstock would be < or = 2.3% of the population. These data suggest that faecal dispersal of C. parvum on back country watersheds is unlikely with packstock.


Asunto(s)
Criptosporidiosis/veterinaria , Cryptosporidium parvum , Equidae/parasitología , Giardiasis/veterinaria , Enfermedades de los Caballos/parasitología , Crianza de Animales Domésticos , Animales , California/epidemiología , Estudios Transversales , Criptosporidiosis/epidemiología , Cryptosporidium parvum/crecimiento & desarrollo , Heces/parasitología , Femenino , Giardia/crecimiento & desarrollo , Giardiasis/epidemiología , Enfermedades de los Caballos/epidemiología , Caballos/parasitología , Masculino , Microscopía Fluorescente/veterinaria , Prevalencia , Análisis de Regresión , Factores de Riesgo
8.
Ginecol Obstet Mex ; 60: 33-6, 1992 Feb.
Artículo en Español | MEDLINE | ID: mdl-1563638

RESUMEN

This paper studies if cerebellum measurement by ultrasound is a point of prognostic value for evaluation of gestational age. Ninety-nine neonates of different age of gestation, were studied. Ultrasonographic study of the cerebellum was done in all the cases during the first 24 hours of life. It is suggested that the cerebellum measurement may be one indicator more for the evaluation of gestational age, and therefore of value to identify the products with growth disturbances.


Asunto(s)
Cerebelo/diagnóstico por imagen , Análisis de Varianza , Peso al Nacer , Edad Gestacional , Humanos , Recién Nacido , Pronóstico , Ultrasonografía
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