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1.
J Zoo Wildl Med ; 55(2): 479-489, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38875206

RESUMO

Aspergillosis is a major cause of morbidity and mortality in penguins, with triazole antifungal drugs being commonly used for prophylaxis and treatment. This report describes 15 cases of fatal hemolysis associated with liquid itraconazole and voriconazole formulations administered to African penguins (Spheniscus demersus) from four institutions. All penguins underwent stressful events (e.g. relocation, induced molt) and were administered commercial liquid itraconazole formulations or compounded voriconazole liquid suspension. Observed clinical signs in affected penguins prior to death included hyporexia, weight loss, lethargy, dyspnea, red-tinged droppings, and obtunded mentation. Intra- and extravascular hemolysis and hemoglobinuric nephrosis were the primary pathologic manifestations on postmortem examination. The concentration-dependent hemolytic potentials of itraconazole, voriconazole, and commercial and compounded vehicle suspensions were evaluated in vitro by exposing chicken whole blood as a surrogate for penguin blood. Hemoglobin content in blood plasma was then measured by spectrophotometry. Neither itraconazole nor voriconazole alone induced hemolysis in vitro. The vehicle ingredients sorbitol and hydromellose induced hemolysis, but not at predicted plasma levels in chicken erythrocytes, suggesting neither the azole antifungals nor their major vehicles alone were likely to contribute to hemolysis in vivo in these penguins. Potential mechanisms of toxicosis include generation of an unmeasured reactive metabolite causing hemolysis, preexisting erythrocyte fragility, or species-specific differences in hemolytic thresholds that were not assessed in the chicken erythrocyte model. More research is needed on the potential for toxicosis of azole antifungal drugs and carrier molecules in this and other avian species.


Assuntos
Antifúngicos , Doenças das Aves , Hemólise , Spheniscidae , Voriconazol , Animais , Doenças das Aves/induzido quimicamente , Doenças das Aves/tratamento farmacológico , Hemólise/efeitos dos fármacos , Antifúngicos/efeitos adversos , Antifúngicos/uso terapêutico , Antifúngicos/administração & dosagem , Voriconazol/efeitos adversos , Voriconazol/uso terapêutico , Itraconazol/efeitos adversos , Itraconazol/uso terapêutico , Itraconazol/administração & dosagem , Triazóis/efeitos adversos , Triazóis/uso terapêutico , Masculino , Feminino , Animais de Zoológico
2.
Vet Pathol ; 60(5): 709-713, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37313845

RESUMO

The amoeba Malpighamoeba mellificae is the etiologic agent of amoebic (amoeba) disease of Western honey bees (Apis mellifera). M. mellificae damages the Malpighian tubules, which is believed to weaken and kill the host bee. Here, the authors describe the detection of this organism in a honey bee colony in the Yukon Territory, Canada. The Malpighian tubules of 14% (7/50) of the adult worker bees were discolored dark brown. Fifteen bees screened using conventional polymerase chain reaction for the 18S gene of M. mellificae were positive for the pathogen. Histologically, the lumens of Malpighian tubules were packed with amoebae, causing dilation of the tubules and attenuation and loss of the tubular epithelium. This phylogenetic analysis places M. mellificae in a new clade, a sister group to the Entamoebidae. This work provides a foundation for further investigation into the distribution, prevalence, and pathology associated with M. mellificae infection.


Assuntos
Amoeba , Abelhas , Animais , Filogenia , Reação em Cadeia da Polimerase/veterinária , Canadá
3.
Phys Rev Lett ; 129(27): 275001, 2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36638294

RESUMO

We present measurements of ice-ablator mix at stagnation of inertially confined, cryogenically layered capsule implosions. An ice layer thickness scan with layers significantly thinner than used in ignition experiments enables us to investigate mix near the inner ablator interface. Our experiments reveal for the first time that the majority of atomically mixed ablator material is "dark" mix. It is seeded by the ice-ablator interface instability and located in the relatively cooler, denser region of the fuel assembly surrounding the fusion hot spot. The amount of dark mix is an important quantity as it is thought to affect both fusion fuel compression and burn propagation when it turns into hot mix as the burn wave propagates through the initially colder fuel region surrounding an igniting hot spot. We demonstrate a significant reduction in ice-ablator mix in the hot-spot boundary region when we increase the initial ice layer thickness.

4.
Phys Rev Lett ; 126(8): 085001, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33709744

RESUMO

In a plasma of sufficient size and density, photons emitted within the system have a probability of being reabsorbed and reemitted multiple times-a phenomenon known in astrophysics as resonant scattering. This effect alters the ratio of optically thick to optically thin lines, depending on the plasma geometry and viewing angle, and has significant implications for the spectra observed in a number of astrophysical scenarios, but has not previously been studied in a controlled laboratory plasma. We demonstrate the effect in the x-ray spectra emitted by cylindrical plasmas generated by high power laser irradiation, and the results confirm the geometrical interpretation of resonant scattering.

5.
Vox Sang ; 116(6): 692-701, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33341965

RESUMO

BACKGROUND AND OBJECTIVES: Red blood cell concentrates (RBCC) are susceptible to bacterial contamination despite cold storage. A reliable evaluation of strategies to minimize the risk of RBCC-associated bacterial transmission requires the use of suitable reference bacteria. Already existing Transfusion-Relevant Bacteria Reference Strains (TRBRS) for platelet concentrates fail to grow in RBCC. Consequently, the ISBT TTID, Working Party, Bacterial Subgroup, conducted an international study on TRBRS for RBCC. MATERIALS AND METHODS: Six bacterial strains (Listeria monocytogenes PEI-A-199, Serratia liquefaciens PEI-A-184, Serratia marcescens PEI-B-P-56, Pseudomonas fluorescens PEI-B-P-77, Yersinia enterocolitica PEI-A-105, Yersinia enterocolitica PEI-A-176) were distributed to 15 laboratories worldwide for enumeration, identification, and determination of growth kinetics in RBCC at days 7, 14, 21, 28, 35 and 42 of storage after low-count spiking (10-25 CFU/RBCC). RESULTS: Bacterial proliferation in RBCC was obtained for most strains, except for S. marcescens, which grew only at 4 of 15 laboratories. S. liquefaciens, S. marcescens, P. fluorescens and the two Y. enterocolitica strains reached the stationary phase between days 14 and 21 of RBCC storage with a bacterial concentration of approximately 109  CFU/ml. L. monocytogenes displayed slower growth kinetics reaching 106 -107  CFU/ml after 42 days. CONCLUSION: The results illustrate the importance of conducting comprehensive studies to establish well-characterized reference strains, which can be a tool to assess strategies and methods used to ameliorate blood safety. The WHO Expert Committee on Biological Standardization adopted the five successful strains as official RBCC reference strains. Our study also highlights the relevance of visual inspection to interdict contaminated RBC units.


Assuntos
Bactérias , Transfusão de Sangue , Eritrócitos , Bactérias/isolamento & purificação , Segurança do Sangue , Contagem de Eritrócitos , Humanos , Valores de Referência
6.
Phys Rev Lett ; 124(14): 145001, 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32338978

RESUMO

The impact to fusion energy production due to the radiative loss from a localized mix in inertial confinement implosions using high density carbon capsule targets has been quantified. The radiative loss from the localized mix and local cooling of the reacting plasma conditions was quantified using neutron and x-ray images to reconstruct the hot spot conditions during thermonuclear burn. Such localized features arise from ablator material that is injected into the hot spot from the Rayleigh-Taylor growth of capsule surface perturbations, particularly the tube used to fill the capsule with deuterium and tritium fuel. Observations, consistent with analytic estimates, show the degradation to fusion energy production to be linearly proportional to the fraction of the total emission that is associated with injected ablator material and that this radiative loss has been the primary source of variations, of up to 1.6 times, in observed fusion energy production. Reducing the fill tube diameter has increased the ignition metric χ_{no α} from 0.49 to 0.72, 92% of that required to achieve a burning hot spot.

7.
Eur J Neurosci ; 45(6): 816-825, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28112452

RESUMO

The neurotransmitter dopamine (DA) is known to be involved in a multitude of physiological processes. We investigated sexually dimorphic effects of disruptions in DA homeostasis and its relationship to senescence using three different Drosophila melanogaster mutants namely Catsup (Catsup26 ) with elevated DA levels, and pale (ple2 ), Punch (PuZ22 ) with depleted DA levels. In all genotypes including controls, DA levels were significantly lower in old (45-50-day-old) flies compared with young (3-5-day-old) in both sexes. Interestingly, females had lower DA content than males at young age whereas this difference was not observed in old age, suggesting that males had a larger decline in DA levels with age. Females, in general, were longer lived compared with males in all genotypes except ple2 mutants with depleted DA levels. This phenotype was abolished in the ple2 rescue flies. Interestingly, females also demonstrated marked age-related decline in circadian locomotor activity compared with males. Old Catsup26 males with elevated DA levels accumulated significantly lower levels of lipid peroxidation product 4-hydroxy 2-nonenal (4-HNE) compared with age-matched wild type, ple2 and PuZ22 mutant males. In Catsup26 revertant lines this phenomenon was absent. We also observed a sexually dimorphic response in the expression levels of key stress and aging associated and/or related transcription factor genes across genotypes with elevated or depleted DA levels which was reverted to wild type levels in specific rescue lines. Taken together, our results reveal a novel sexually dimorphic involvement of DA in senescence characteristics of D. melanogaster.


Assuntos
Envelhecimento/metabolismo , Dopamina/metabolismo , Homeostase , Envelhecimento/genética , Animais , Relógios Circadianos , Dopamina/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Feminino , Genótipo , Peroxidação de Lipídeos , Locomoção , Masculino , Fatores Sexuais
8.
J Virol Methods ; 328: 114953, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38759872

RESUMO

Viruses in the families Dicistroviridae and Iflaviridae are among the main threats to western honey bees (Apis mellifera) and native bee species. Polymerase chain reaction (PCR) is the gold standard for pathogen detection in bees. However, high throughput screening for bee virus infections in singleplex PCR reactions is cumbersome and limited by the high quantities of sample RNA required. Thus, the development of a sensitive and specific multiplex PCR detection method for screening for multiple viruses simultaneously is necessary. Here, we report the development of a one-step multiplex reverse-transcription quantitative polymerase chain reaction (RT-qPCR) assay to detect four viruses commonly encountered in pollinator species. The optimized multiplex RT-qPCR protocol described in this study allows simultaneous detection of two dicistroviruses (Israeli acute paralysis virus and Black queen cell virus) and two iflaviruses (Sacbrood virus and Deformed wing virus) with high efficiency and specificity comparable to singleplex detection assays. This assay provides a broad range of detection and quantification, and the results of virus quantification in this study are similar to those performed in other studies using singleplex detection assays. This method will be particularly useful for data generation from small-bodied insect species that yield low amounts of RNA.


Assuntos
Dicistroviridae , Reação em Cadeia da Polimerase Multiplex , Vírus de RNA , Sensibilidade e Especificidade , Animais , Abelhas/virologia , Reação em Cadeia da Polimerase Multiplex/métodos , Dicistroviridae/isolamento & purificação , Dicistroviridae/genética , Vírus de RNA/genética , Vírus de RNA/isolamento & purificação , Vírus de RNA/classificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Vírus de Insetos/isolamento & purificação , Vírus de Insetos/genética , Vírus de Insetos/classificação , RNA Viral/genética , RNA Viral/isolamento & purificação
9.
Animals (Basel) ; 14(10)2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38791728

RESUMO

A 7-year-old farmed white-tailed deer doe was transported to a Levy County, Florida property and began to decline in health, exhibiting weight loss and pelvic limb weakness. The doe prematurely delivered live twin fawns, both of which later died. The doe was treated with corticosteroids, antibiotics, gastric cytoprotectants, and B vitamins but showed no improvement. The doe was euthanized, and a post mortem examination was performed under the University of Florida's Cervidae Health Research Initiative. We collected lung tissue after the animal was euthanized and performed histological evaluation, using H&E and Ziehl-Neelsen (ZN) staining, and molecular evaluation, using conventional PCR, followed by Sanger sequencing. The microscopic observations of the H&E-stained lung showed multifocal granuloma, while the ZN-stained tissue revealed low numbers of beaded, magenta-staining rod bacteria inside the granuloma formation. Molecular analysis identified the presence of Mycobacterium kansasii. This isolation of a non-tuberculous Mycobacterium in a white-tailed deer emphasizes the importance of specific pathogen identification in cases of tuberculosis-like disease in farmed and free-ranging cervids. We report the first case of M. kansasii infection in a farmed white-tailed deer (Odocoileus virginianus) in Florida. Although M. kansasii cases are sporadic in white-tailed deer, it is important to maintain farm biosecurity and prevent farmed cervids from contacting wildlife to prevent disease transmission.

10.
Ann Oncol ; 24(4): 960-5, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23175623

RESUMO

BACKGROUND: A previous study has shown that shorter bevacizumab infusions (0.5 mg/kg/min) can be safely administered without increasing the risk of infusion-related hypersensitivity reactions (HSRs). However, the risk of proteinuria and hypertension in patients receiving shorter infusions of bevacizumab is undetermined. PATIENTS AND METHODS: This was a multicenter, prospective, observational study in patients receiving <10 mg/kg of bevacizumab infused over 0.5 mg/kg/min. Patients were observed until discontinuation of bevacizumab for progression of cancer or toxicity. The incidence of hypertension and proteinuria was compared with a prior cohort of patients who had received standard duration infusions of bevacizumab. RESULTS: Sixty-three patients received a total of 392 doses of shorter bevacizumab infusions. Nineteen (30.2%) patients experienced proteinuria while receiving bevacizumab. Out of 19 patients, 13 had grade 1 and 6 had grade 2 proteinuria. None of the patients experienced grade 3 or 4 proteinuria. Hypertension was reported in 32 (50.8%) patients receiving bevacizumab. Twelve (19%) patients developed grade 3 or greater hypertension on bevacizumab. The incidence of proteinuria and hypertension was 38.3% and 56.6%, respectively, in patients (N = 120, 1347 infusions) receiving standard duration infusions of bevacizumab. CONCLUSIONS: Shorter bevacizumab infusions (0.5 mg/kg/min) do not increase the risk of proteinuria and hypertension.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Neoplasias Colorretais/tratamento farmacológico , Hipertensão/patologia , Proteinúria/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Bevacizumab , Neoplasias Colorretais/complicações , Neoplasias Colorretais/patologia , Progressão da Doença , Esquema de Medicação , Feminino , Humanos , Hipertensão/induzido quimicamente , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Proteinúria/induzido quimicamente
11.
Phys Rev Lett ; 110(26): 265003, 2013 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-23848885

RESUMO

The newly commissioned Orion laser system has been used to study dense plasmas created by a combination of short pulse laser heating and compression by laser driven shocks. Thus the plasma density was systematically varied between 1 and 10 g/cc by using aluminum samples buried in plastic foils or diamond sheets. The aluminum was heated to electron temperatures between 500 and 700 eV allowing the plasma conditions to be diagnosed by K-shell emission spectroscopy. The K-shell spectra show the effect of the ionization potential depression as a function of density. The data are compared to simulated spectra which account for the change in the ionization potential by the commonly used Stewart and Pyatt prescription and an alternative due to Ecker and Kröll suggested by recent x-ray free-electron laser experiments. The experimental data are in closer agreement with simulations using the model of Stewart and Pyatt.

12.
Animals (Basel) ; 12(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35681837

RESUMO

Lower survival has been reported in foals than adults with small intestinal strangulating obstruction (SISO), but age-dependent outcomes have not been examined directly. Hospital records were collected from five US academic referral hospitals. It was hypothesized that foals would exhibit lower survival than case-matched adults. Foal cases 6-months-of-age or younger, and adult cases between 2- and 20-years-of-age were collected. Data revealed 24 of 25 (96.0%) foals and 66 of 75 (88.0%) adults that were recovered from surgery for SISO survived to hospital discharge. Sixteen of the total 41 (39.0%) foals studied were euthanized intraoperatively, whereas 30 of 105 (28.6%) adults were euthanized intraoperatively. Common lesions in foals that were recovered from surgery were volvulus (n = 13) and intussusception (n = 5), whereas common lesions in adults were volvulus (n = 25) and strangulating lipoma (n = 23). This study was limited by incomplete medical records, relatively small sample size, and lack of long-term follow-up. Unexpectedly, short-term survival tended to be higher in foals than adults and may have been partly driven by case selection prior to referral or surgery or decision-making intraoperatively. More optimism toward surgical treatment of foals with SISO may be warranted.

13.
Viruses ; 14(12)2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36560729

RESUMO

Burmese python (Python bivittatus) is an invasive snake that has significantly affected ecosystems in southern Florida, United States. Aside from direct predation and competition, invasive species can also introduce nonnative pathogens that can adversely affect native species. The subfamily Serpentovirinae (order Nidovirales) is composed of positive-sense RNA viruses primarily found in reptiles. Some serpentoviruses, such as shingleback nidovirus, are associated with mortalities in wild populations, while others, including ball python nidovirus and green tree python nidovirus can be a major cause of disease and mortality in captive animals. To determine if serpentoviruses were present in invasive Burmese pythons in southern Florida, oral swabs were collected from both free-ranging and long-term captive snakes. Swabs were screened for the presence of serpentovirus by reverse transcription PCR and sequenced. A total serpentovirus prevalence of 27.8% was detected in 318 python samples. Of the initial swabs from 172 free-ranging pythons, 42 (24.4%) were positive for multiple divergent viral sequences comprising four clades across the sampling range. Both sex and snout-vent length were statistically significant factors in virus prevalence, with larger male snakes having the highest prevalence. Sampling location was statistically significant in circulating virus sequence. Mild clinical signs and lesions consistent with serpentovirus infection were observed in a subset of sampled pythons. Testing of native snakes (n = 219, 18 species) in part of the python range found no evidence of python virus spillover; however, five individual native snakes (2.3%) representing three species were PCR positive for unique, divergent serpentoviruses. Calculated pairwise uncorrected distance analysis indicated the newly discovered virus sequences likely represent three novel genera in the subfamily Serpentovirinae. This study is the first to characterize serpentovirus in wild free-ranging pythons or in any free-ranging North America reptile. Though the risk these viruses pose to the invasive and native species is unknown, the potential for spillover to native herpetofauna warrants further investigation.


Assuntos
Boidae , Nidovirales , Animais , Florida/epidemiologia , Ecossistema , Espécies Introduzidas
14.
Rev Sci Instrum ; 92(3): 033502, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33820003

RESUMO

In this work, we present the measurement of L-band emission from buried Sc/V targets in experiments performed at the OMEGA laser facility. The goal of these experiments was to study non-local thermodynamic equilibrium plasmas and benchmark atomic physics codes. The L-band emission was measured simultaneously by the time resolved DANTE power diagnostic and the recently fielded time integrated Soreq-Transmission Grating Spectrometer (TGS) diagnostic. The TGS measurement was used to support the spectral reconstruction process needed for the unfolding of the DANTE data. The Soreq-TGS diagnostic allows for broadband spectral measurement in the 120 eV-2000 eV spectral band, covering L- and M-shell emission of mid- and high-Z elements, with spectral resolution λ/Δλ = 8-30 and accuracy better than 25%. The Soreq-TGS diagnostic is compatible with ten-inch-manipulator platforms and can be used for a wide variety of high energy density physics, laboratory astrophysics, and inertial confinement fusion experiments.

15.
Front Vet Sci ; 7: 594600, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33490131

RESUMO

Ball pythons (Python regius) are one of the most commonly kept and bred reptiles in captivity. In a large ball python breeding colony, a unique syndrome characterized by granulomatous inflammation of the cloaca and hemipenes (phalli) was observed in 140 of 481 (29.1%) breeding males, but only one of 1,446 breeding females. Lesions were absent in virgin males (n = 201) and virgin females (n = 293). On postmortem examination (n = 13, 12 males, 1 female), numerous well-defined mucosal and submucosal granulomas were present in the hemipenes (males) and cloaca (males and female). Extension into the coelomic cavity and liver was noted in a subset of these animals. An additional small subset of breeder animals (6/2027; 0.3%) presented with oral and mandibular swellings. Postmortem examination (n = 4, all female) showed oral lesions histologically indistinguishable from the cloacal/hemipenal lesions. Aerobic bacterial culture of a hepatic granuloma of one snake resulted in the isolation of filamentous, Gram-positive bacilli; amplification, and sequencing of the 16S rRNA gene and subsequent phylogenetic analysis of the isolate identified the bacterium as a novel species of Actinomyces. Screening of cloacal and oral granulomas using a specific, heminested 16S rRNA PCR assay confirmed the presence of the agent in all 17 snakes, as well as in cloacal swabs taken at the time of necropsy in 11/13 snakes. The Actinomyces sp. was also identified by PCR of cloacal swabs of unaffected snakes (n = 94) from the affected colony and two unrelated, grossly unaffected breeding colonies. In the affected colony, 65.5% of breeding animals (n = 23) but only 11.9% of virgin animals (n = 42) tested PCR positive, with breeding status being a significant predictor of bacterium presence (P < 0.00001). This study characterizes a granulomatous mucosal disease syndrome of breeding male ball pythons associated with a novel Actinomyces. In stark contrast to male snakes, the presence of the bacterium in both breeding and virgin females was very rarely associated with clinical disease. Though additional studies are necessary, these data suggest a role for the novel bacterium in the disease process, a predilection for clinical disease in male snakes, and the potential for sexual transmission of the disease.

16.
Front Vet Sci ; 7: 467, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32851040

RESUMO

Raillietiella orientalis is an obligate, crustacean parasite that resides in the respiratory tract of definitive snake hosts. Common throughout southeastern Asia and Australia, R. orientalis is believed to have been introduced into southern Florida, United States along with Burmese pythons (Python bivittatus) in the 1990s. While the invasive range of Burmese pythons is restricted to southern Florida, R. orientalis has advanced north in the state in native snake species. R. orientalis were recovered from the lungs, trachea, oral cavity, and esophagus of an emaciated adult female free-ranging banded water snake (Nerodia fasciata) in north central (Alachua County), Florida, USA. Concurrent findings included the recovery of Ochetosoma sp. trematodes from the oral cavity, and multifocal dermal lesions consistent with snake fungal disease (Ophidiomyces ophiodiicola). This is the first report of R. orientalis in north central Florida, well outside the invasive range of the Burmese python, documenting the substantial northward expansion of the known geographical range of this invasive pentastome in Florida.

17.
Rev Sci Instrum ; 89(10): 10F106, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399788

RESUMO

K-shell x-ray spectra of Li- to H-like ions have long been used to determine plasma conditions. The ratio of integrated line intensities is used to determine the temperature. At the density of non-local thermal dynamic equilibrium (NLTE) plasmas (n e ≈ 1021 cm-3), the K-shell spectrum is not very sensitive to density. We propose using the L-shell emission of open L-shell ions (C- to Li-like) as an alternative to determine both temperature and density of NLTE plasmas. First, the L-shell models of a mid-Z material need to be verified against the temperatures obtained using a K-shell spectrum of a low-Z material. A buried layer platform is being developed at the OMEGA laser to study the open L-shell spectra of NLTE plasmas of mid-Z materials. Studies have been done using a 250 µm diameter dot composed of a layer of 1200 Å thick Zn between two 600 Å thick layers of Ti, in the center of a 1000 µm diameter, 13 µm thick beryllium tamper. Lasers heat the target from both sides for up to 3 ns. The size of the emitting volume vs time was measured with x-ray imaging (face-on and side-on) to determine the density. The temperature was measured from the Ti K-shell spectra. The use of this platform for the verification of atomic L-shell models is discussed.

18.
J AOAC Int ; 101(3): 831-842, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29021006

RESUMO

Single- and multilaboratory testing data have provided systematic scientific evidence that a simple, selective, accurate, and precise method can be used as a potential candidate reference method for dispute resolution in determining total biotin in all forms of infant, adult, and/or pediatric formula. Using LC coupled with immunoaffinity column cleanup extraction, the method fully meets the intended purpose and applicability statement in AOAC Standard Method Performance Requirement 2014.005. The method was applied to a cross-section of infant formula and adult nutritional matrixes, and acceptable precision and accuracy were established. The analytical platform is inexpensive, and the method can be used in almost any laboratory worldwide with basic facilities. The immunoaffinity column cleanup extraction is the key step to successful analysis.


Assuntos
Biotina/análise , Cromatografia de Afinidade/métodos , Cromatografia Líquida/métodos , Fórmulas Infantis/análise , Adulto , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Lisina/análogos & derivados , Lisina/análise , Reprodutibilidade dos Testes
19.
J Chromatogr A ; 1101(1-2): 63-8, 2006 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-16216253

RESUMO

A new, faster and simple method to quantify Vitamin B12, both in foods and in premixes, by reversed-phase liquid chromatography with UV detection has been developed. Vitamin B12 was extracted from food products with 50 mM sodium acetate buffer pH 4.0 (at 100 degrees C for 35 min) in the presence of sodium cyanide, followed by a purification step on an immunoaffinity column prior to the LC analysis. An enzymatic hydrolysis (pepsin at 37 degrees C and pH 4 for 3 h) prior to the purification step efficiently released the bound Vitamin B12, and thus, allowed obtaining total Vitamin B12 content in food products. Vitamin B12 was monitored by UV at 361 nm after its separation on a reversed-phase narrow-bore column with a gradient of mobile phase made of water/acetonitrile and trifluoroacetic acid (TFA) 0.025%. The specificity of the method was demonstrated by the retention characteristics, UV spectra and by comparing the peak purity with the Vitamin B12 standard. The calibration graphs plotted with six concentrations of Vitamin B12 was linear with a regression coefficient R2 > 0.9997. The repeatability of the method was evaluated at different levels of concentration on six fortified products and the relative standard deviation (RSDr) was below 3.2%. The value of the relative standard deviation of the intermediate precision was below 5.6% (n = 4). The method was successfully applied to several food products and consistent results were obtained in comparison with microbiological assay (MBA). Our data demonstrate that the immunoaffinity columns are highly efficient for the purification of Vitamin B12 and that our HPLC could be used as an alternative method to the microbiological assay for the determination of Vitamin B12 in food products.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Vitamina B 12/análise , Cromatografia de Afinidade/métodos , Fórmulas Infantis/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Raios Ultravioleta , Vitamina B 12/isolamento & purificação
20.
J Am Vet Med Assoc ; 257(2): 151-155, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32597726
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