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1.
Phys Rev E ; 109(2-2): 025208, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38491688

RESUMEN

It was observed experimentally that after crossing a waveguide filled with a neutral gas a short powerful microwave pulse leaves a periodic glow of plasma along the waveguide, persisting for several tens of nanoseconds. A theoretical model is presented which in combination with numerical simulations proposes a possible explanation for this phenomenon.

2.
Climacteric ; 27(1): 104-112, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38197424

RESUMEN

Ischemic heart disease is the primary cause of cardiovascular disease (CVD) mortality in both men and women. Strategies targeting traditional modifiable risk factors are essential - including hypertension, smoking, dyslipidemia and diabetes mellitus - particularly for atherosclerosis, but additionally for stroke, heart failure and some arrhythmias. However, challenges related to education, screening and equitable access to effective preventative therapies persist, and are particularly problematic for women around the globe and those from lower socioeconomic groups. The association of female-specific risk factors (e.g. premature menopause, gestational hypertension, small for gestational age births) with CVD provides a potential window for targeted prevention strategies. However, further evidence for specific effective screening and interventions is urgently required. In addition to population-level factors involved in increasing the risk of suffering a CVD event, efforts are leveraging the enormous potential of blood-based 'omics', improved imaging biomarkers and increasingly complex bioinformatic analytic approaches to strive toward more personalized early disease detection and personalized preventative therapies. These novel tactics may be particularly relevant for women in whom traditional risk factors perform poorly. Here we discuss established and emerging approaches for improving risk assessment, early disease detection and effective preventative strategies to reduce the mammoth burden of CVD in women.


Asunto(s)
Enfermedades Cardiovasculares , Hipertensión , Masculino , Humanos , Femenino , Enfermedades Cardiovasculares/prevención & control , Enfermedades Cardiovasculares/etiología , Factores de Riesgo , Medición de Riesgo , Prevención Primaria
3.
Phys Rev E ; 107(4-2): 045203, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37198856

RESUMEN

Frequency up-conversion (∼10%) and compression (almost twofold) of a powerful (≤250 MW) microwave pulse in the propagating ionization front produced by the pulse itself in a gas-filled waveguide, is investigated experimentally and analyzed theoretically. Pulse envelope reshaping and group velocity increase manifest themselves in a propagation of the pulse faster than in the empty waveguide. A simple one-dimensional mathematical model allows the adequate interpretation of the experimental results.

4.
Rev Sci Instrum ; 92(2): 023510, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33648154

RESUMEN

We present the design and parameters of a compact and mobile high-current pulse generator, which can be applied in the study of warm dense matter in university laboratories. The generator dimensions are 550 × 570 × 590 mm3, the weight is ∼70 kg, and it consists of four "bricks" connected in parallel. Each brick, made up of 2 × 40 nF, 100 kV low-inductance capacitors connected in parallel, has its own multi-gap and multichannel ball gas spark switch, triggered via a capacitively coupled triggering by a positive polarity pulse of ∼80 kV amplitude and ∼15 ns rise time. At a charging voltage of ∼70 kV, the generator produces a ∼155 kA current pulse with a rise time of ∼220 ns on a ∼15 nH inductive short-circuit load and a ∼90 kA amplitude current pulse in the underwater electrical explosion of a copper wire.

5.
Animal ; 15(1): 100003, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33516011

RESUMEN

Alternatives to riboflavin (vitamin B2) production by recombinant microorganisms are needed in organic poultry production, but are cost-intensive, so that a demand-oriented riboflavin supply is necessary. Details on the riboflavin requirements of organic poultry are not available. A feed material with high native riboflavin content from fermentation of the filamentous fungus Ashbya gossypii was studied. Two runs with 800 Ranger Gold™ broilers each (40 pens with 20 animals) were conducted. The fattening period was divided into starter (S), grower (G) and finisher (F) stage. In the first run, a basal diet without riboflavin supplementation (NATIVE; 3.27, 3.50 and 3.16 mg riboflavin/kg DM in S, G and F) was compared to diets with supplementation at low (LOW; 5.30, 4.85 and 5.19 mg/kg in S, G and F), medium (MEDIUM; 7.56, 6.88 and 7.56 mg/kg in S, G and F) and high (HIGH; 10.38, 9.14 and 9.93 mg/kg in S, G and F) dosage. In the second run, different combinations of low and medium riboflavin supplementation were used in S, G and F diets: S-LOW (4.50 mg riboflavin/kg DM), G-MEDIUM (6.66 mg/kg), F-MEDIUM (5.71 mg/kg) (Treatment A), S-LOW (4.50 mg riboflavin/kg DM); G-LOW (4.92 mg/kg), F-LOW (4.01 mg/kg) (Treatment B); S-MEDIUM (6.37 mg/kg), G-MEDIUM (7.37 mg/kg), F-MEDIUM (5.07 mg/kg) (Treatment C); S-MEDIUM (6.37 mg/kg), G-LOW (5.28 mg/kg), F-LOW (4.22 mg/kg) (Treatment D). Body weight, feed and water consumption were recorded weekly, health and welfare indicators were scored bi-weekly. Slaughter traits were assessed for five males and females per pen. In the first run, NATIVE animals showed symptoms of riboflavin deficiency and lower live weights in the second week of age. Riboflavin contents of this group were increased to avoid further deficiency and recovery was observed. Feed conversion was better in HIGH (2.07) compared with NATIVE and LOW (2.11). At slaughter, treatments differed neither for foot pad dermatitis nor plumage cleanliness. In the second run, daily weight gains did not differ between treatments in any of the weeks. Feed conversion ranged between 1.99 and 2.04. Riboflavin deficiency was not observed in the second run, while treatment D showed superior economic efficiency. In conclusion, native contents of feed components (3.27 mg/kg DM) were not sufficient to meet the riboflavin demand and a total content of 4.50 mg/kg DM was identified as safe lower threshold. The levels rather according to commercial recommendations were not additionally beneficial to performance and health.


Asunto(s)
Alimentación Animal , Eremothecium , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Pollos , Dieta/veterinaria , Femenino , Fermentación , Masculino , Riboflavina
6.
Animal ; 14(4): 716-724, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31623698

RESUMEN

Riboflavin (vitamin B2) is essential for monogastric animals. It is mainly produced by recombinant microorganisms (Candida famata, Bacillus subtilis and Ashbya gossypii). The availability of genetically modified organism (GMO)-free riboflavin, obligatory in European organic agriculture, is a major issue. Besides, requirements for organic livestock might differ from conventional production because other genotypes and feed formulations are used. The effects of a fermentation suspension with a high native content of riboflavin produced with unmodified A. gossypii by fermentation were investigated at graded dosages as an alternative to conventional (GMO-based) riboflavin in slow-growing broilers on performance traits and health and welfare indicators. In 2 runs with 800 animals each, Ranger Gold™ broilers were fed with 4 dietary treatments. For starter diets (day 1 to 18), treatments included a basal diet (1) without any riboflavin supplementation (negative control, N-C), (2) with conventional riboflavin supplementation (Cuxavit B2 80% riboflavin) at 9.6 mg/kg (positive control, P-C), (3) with riboflavin supplementation from the alternative source at 3.5 mg/kg (A-low) and (4) with riboflavin supplementation from the alternative source at 9.6 mg/kg (A-high). For the finisher diet (day 29 until slaughtering), P-C and A-high were supplemented with 8.0 mg/kg and A-low with 3.5 mg/kg. Diets were formulated according to organic regulations. Animals were kept in floor pens with 20 chickens per pen. Weekly, BW, feed and water consumption were recorded. Every second week, animal-based health and welfare indicators (feather score and footpad dermatitis) were scored. Slaughter traits were assessed for five males and females per pen at 62/63 days of age. Final body weight of A-high differed from N-C and A-low, but not from P-C. From week 2 until six years of age, A-high had a higher daily weight gain when compared to all other groups. With 74.4%, dressing percentage was higher in A-high compared with all other groups (73.3%). Breast percentage of A-low was lower than that of both control groups but did not differ from A-high. The highest frequency of liver scores indicating fatty liver syndrome was found in P-C, followed by N-C and A-low. Feather scores did not respond to treatment; the highest frequency of mild footpad dermatitis was observed in A-high, however at a low prevalence. In conclusion, the tested fermentation suspension with a high native content of riboflavin derived from fermentation of A. gossypii can be used at levels of commercial recommendations as alternative to riboflavin produced from GMO in broiler feeding. Further studies must verify whether riboflavin can be reduced without inducing riboflavin deficiency in slow-growing broilers.


Asunto(s)
Pollos/fisiología , Suplementos Dietéticos/análisis , Eremothecium/fisiología , Riboflavina/análisis , Alimentación Animal/análisis , Animales , Peso Corporal , Dieta/veterinaria , Plumas , Femenino , Fermentación , Estado de Salud , Masculino
8.
PLoS One ; 14(3): e0213319, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30875374

RESUMEN

OBJECTIVE: To determine if corneal confocal microscopy can identify corneal nerve and endothelial cell abnormalities and may be useful in the prognostication of patients with transient ischemic attack [1] or minor ischemic stroke (IS). METHODS: Thirty-six patients admitted with TIA (n = 14) or minor IS (n = 22) underwent transcranial Doppler evaluation and corneal confocal microscopy and were compared with 18 healthy controls. RESULTS: Corneal nerve fiber density (P = 0.002), branch density (P = 0.004) and fiber length (P = 0.004) were significantly lower in patients with TIA or minor IS compared to controls, with no difference between patients with TIA and minor IS. Endothelial cell density (P = 0.003) was lower and endothelial cell area (P = 0.003) and perimeter (P = 0.006) were significantly higher in patients with TIA or minor IS compared to controls, with no difference between patients with TIA and minor IS. There were no differences in corneal nerve or endothelial cell morphology between patients with and without abnormal cerebrovascular reactivity. HbA1c was independently associated with CNFL, and endothelial cell polymegathism and pleomorphism were associated with both HbA1c and total cholesterol. CONCLUSION: Corneal confocal microscopy identifies corneal nerve fiber loss and endothelial cell abnormalities in patients with TIA and minor IS and independent associations with HbA1c and cholesterol.


Asunto(s)
Isquemia Encefálica/fisiopatología , Córnea/inervación , Endotelio Vascular/patología , Ataque Isquémico Transitorio/fisiopatología , Fibras Nerviosas/patología , Accidente Cerebrovascular/fisiopatología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Microscopía Confocal , Persona de Mediana Edad , Adulto Joven
9.
Phys Rev Lett ; 120(13): 135003, 2018 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-29694181

RESUMEN

Ionization-induced self-channeling of a ≤500 MW, 9.6 GHz, <1 ns microwave beam injected into air at ∼4.5×10^{3} Pa or He at ∼10^{3} Pa is experimentally demonstrated for the first time. The plasma, generated by the impact ionization of the gas driven by the microwave beam, has a radial density distribution reducing towards the beam axis, where the microwave field is highest, because the ionization rate is a decreasing function of the microwave amplitude. This forms a plasma channel which prevents the divergence of the microwave beam. The experimental data obtained using various diagnostic methods are in good agreement with the results of analytical calculations, as well as particle in cell Monte Carlo collisional modeling.

10.
Ann Intensive Care ; 6(1): 68, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27436191

RESUMEN

BACKGROUND: Microdialysis is a well-established technology that can be used for continuous blood glucose monitoring. We determined point and trend accuracy, and reliability of a microdialysis-based continuous blood glucose-monitoring device (EIRUS(®)) in critically ill patients. METHODS: Prospective study involving patients with an expected intensive care unit stay of ≥48 h. Every 15 min, device readings were compared with blood glucose values measured in arterial blood during blocks of 8 h per day for a maximum of 3 days. The Clarke error grid, Bland-Altman plot, mean absolute relative difference and glucose prediction error analysis were used to express point accuracy and the rate error grid to express trend accuracy. Reliability testing included aspects of the device and the external sensor, and the special central venous catheter (CVC) with a semipermeable membrane for use with this device. RESULTS: We collected 594 paired values in 12 patients (65 [26-80; 8-97] (median [IQR; total range]) paired values per patient). Point accuracy: 93.6 % of paired values were in zone A of the Clarke error grid, 6.4 % were in zone B; bias was 4.1 mg/dL with an upper limit of agreement of 28.6 mg/dL and a lower level of agreement of -20.5 mg/dL in the Bland-Altman analysis; 93.6 % of the values ≥75 mg/dL were within 20 % of the reference values in the glucose prediction error analysis; the mean absolute relative difference was 7.5 %. Trend accuracy: 96.4 % of the paired values were in zone A, and 3.3 and 0.3 % were in zone B and zone C of the rate error grid. Reliability: out of 16 sensors, 4 had to be replaced prematurely; out of 12 CVCs, two malfunctioned (one after unintentional flushing by unsupervised nurses of the ports connected to the internal microdialysis chamber, causing rupture of the semipermeable membrane; one for an unknown reason). Device start-up time was 58 [56-67] min; availability of real-time data was 100 % of the connection time. CONCLUSIONS: In this study in critically ill patients who had no hypoglycemic episodes and a limited number of hyperglycemic excursions, point accuracy of the device was moderate to good. Trend accuracy was very good. The device had no downtimes, but 4 out of 16 external sensors and 2 out of 12 CVCs had practical problems.

11.
Phys Rev Lett ; 108(15): 155003, 2012 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-22587262

RESUMEN

We report the first demonstration of magnetically induced transmission in an opaque magnetized plasma. Magnetically induced transmission in a plasma is a classical analog to the electromagnetically induced transparency in atomic systems. The transmission of radiation through an axially magnetized plasma is obtained by applying an additional one dimensional transverse spatial periodic magnetic field. The transverse-periodic magnetic field uncouples the right-hand electromagnetic wave from interacting with plasma electrons, rendering the plasma band-stop transparent. This provides means to control the extent of absorption of electromagnetic radiation in magnetized plasma.

12.
Langmuir ; 28(17): 6942-9, 2012 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-22458322

RESUMEN

In nanobiotechnology, the properties of surfaces are often key to sensor applications. If analytes possess a low tolerance or affinity regarding the sensory substrate (surface), then the setup of mediators may be indicated. Hydrophobins enable biocompatible surface functionalization without significant restrictions of the physicochemical substrate properties. Because of the imperfect formation of hydrophobin films, a high variation in surface properties is observed. In this study, we report on the relation between the film thickness of hydrophobin-coated solid surfaces and their wettability. We found that the wettability of protein-coated surfaces strictly depends on the amount of adsorbed protein, as reflected in an oscillation of the contact angles of hydrophobin-coated silicon wafers. Fusion proteins of Ccg2 and HFBI, representatives of class I and II hydrophobins, document the influence of fused peptide tags on the wettability. The orientation of the first crystal nuclei plays a decisive role in the formation of the growing hydrophobin layers. Here, a simple method of deducing the film thickness of hydrophobin assemblies on solid surfaces is presented. The determination of the static contact angle allows the prediction of which part of the protein is exposed to possible analytes.


Asunto(s)
Proteínas Fúngicas/química , Humectabilidad , Adsorción , Interacciones Hidrofóbicas e Hidrofílicas , Dióxido de Silicio/química , Trichoderma
16.
Immunopharmacol Immunotoxicol ; 28(1): 175-83, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16684676

RESUMEN

The parenteral iron administration effects on the acceleration of lymphomagenesis by radiofrequency exposure were investigated using an animal model that develops spontaneous lymphomas with ageing. Complementary studies of the in vivo uptake of 59Fe-labeled ferric gluconate and ferric-ATP complex showed differences ob absorption and excretion between both iron compounds. In vitro assays of their effects on calcium cellular uptake using a cell model and tissues homogenates showed a molecular structure-dependence. The current results (mortality, clinical and histopathological examinations) demonstrated a synergism between radiofrequency and ferric gluconate, and the increased risk of radiofrequency exposure when it is simultaneous to parenteral iron administration.


Asunto(s)
Hierro/toxicidad , Linfoma/etiología , Neoplasias Inducidas por Radiación/patología , Ondas de Radio , Adenosina Trifosfato/farmacología , Animales , Transporte Biológico Activo/efectos de los fármacos , Recuento de Células Sanguíneas , Calcio/metabolismo , Carcinoma de Ehrlich/patología , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Femenino , Compuestos Férricos/farmacología , Hierro/farmacocinética , Compuestos de Hierro/farmacocinética , Radioisótopos de Hierro , Recuento de Leucocitos , Peroxidación de Lípido/efectos de los fármacos , Linfoma/inducido químicamente , Linfoma/mortalidad , Ratones , Ratones Endogámicos , Miocardio/citología , Distribución Tisular
17.
Eur J Cancer Prev ; 15(3): 191-5, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16679860

RESUMEN

The acceleration of carcinogenesis, which was induced either by radio frequency radiation from a cellular telephone or by the ferric-ATP complex, was similar in a mouse strain characterized by age-determined carcinogenesis of lymphoid tissues. Organ hypertrophy, the presence of lymphoid blood and ascites, the development of solid tumours, and mortality were very different to those found in control animals. These results emphasize the role of calcium ion signal influx in the activation of oncogenes and the failure of thymus-determined immune defences.


Asunto(s)
Calcio/fisiología , Neoplasias/etiología , Ondas de Radio/efectos adversos , Adenoma/etiología , Adenoma/patología , Adenosina Trifosfato/farmacología , Animales , Encéfalo/efectos de los fármacos , Encéfalo/patología , Canales de Calcio/fisiología , Pruebas de Carcinogenicidad/métodos , Extremidades/patología , Femenino , Compuestos Férricos/farmacología , Riñón/efectos de los fármacos , Riñón/patología , Leiomiosarcoma/etiología , Infiltración Leucémica/etiología , Hígado/efectos de los fármacos , Hígado/patología , Pulmón/efectos de los fármacos , Pulmón/patología , Neoplasias Pulmonares/etiología , Neoplasias Pulmonares/patología , Linfoma/etiología , Ratones , Modelos Animales , Ovario/efectos de los fármacos , Ovario/patología , Medición de Riesgo , Transducción de Señal/efectos de la radiación , Bazo/efectos de los fármacos , Bazo/patología
18.
Biol Trace Elem Res ; 108(1-3): 69-75, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16327061

RESUMEN

The roles of sodium-ATP (NaATP) and ferric-ATP complex (FeATP) on the proliferation and infiltration of lymphocytes have been studied by evaluation of the hypertrophy and histopathologic examination of spleen and liver, as well of the modifications in the elemental balance of iron, calcium, magnesium, and phosphorus. The results showed that in the implicated biochemical processes, calcium and magnesium have a principal role. An in vitro study on a cell model has permited one to evaluate the effects of deferoxamine, a known iron chelator and inhibitor of human lymphocyte proliferation, on FeATP-modified cellular calcium fluxes. These findings showing a reduced 45Ca2+ uptake in the presence of deferoxamine appear to indicate that in vivo the chelation of blood-borne iron by ATP might play a key role in proliferation and infiltration of lymphocytes, leading to lymphoma development.


Asunto(s)
Adenosina Trifosfato/metabolismo , Calcio/metabolismo , Hierro/metabolismo , Activación de Linfocitos/efectos de los fármacos , Animales , Carcinoma de Ehrlich/metabolismo , Deferoxamina/metabolismo , Deferoxamina/farmacología , Femenino , Homeostasis/efectos de los fármacos , Humanos , Quelantes del Hierro/metabolismo , Quelantes del Hierro/farmacología , Hígado/efectos de los fármacos , Hígado/patología , Linfoma/metabolismo , Magnesio/metabolismo , Ratones , Fósforo/metabolismo , Bazo/efectos de los fármacos , Bazo/patología
19.
Leukemia ; 19(9): 1543-9, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16001087

RESUMEN

We investigated the constitutive activation of the MEK/ERK pathway in acute myelogenous leukemia (AML) via a flow cytometric technique to quantitate expression of phosphorylated ERK (p-ERK). A total of 42 AML samples (16 newly diagnosed, 26 relapsed/refractory) were analyzed. Normal bone marrow CD34+ cells (n = 10) had little or no expression of p-ERK, while G-CSF-mobilized CD34+ cells exhibited enhanced p-ERK levels. Markedly elevated p-ERK levels were found in 83.3% of the AML samples, with no differences observed between the newly diagnosed and relapsed/refractory samples. Treatment with a MEK inhibitor resulted in significantly decreased p-ERK levels in both the newly diagnosed and relapsed/refractory samples, which was associated with growth arrest, but not apoptosis induction. In summary, we defined conditions for the analysis of MAPK signaling in primary AML samples. Normal CD34+ cells expressed very low levels of p-ERK, and increased p-ERK levels were found in normal G-CSF-stimulated circulating CD34+ cells. Constitutively high p-ERK levels observed in the majority of AML samples suggest deregulation of this pathway that appears to be independent of disease status. The ability of ERK inhibition to promote growth arrest rather than apoptosis suggests that clinical trials of MEK/ERK inhibitors may be more effective when combined with chemotherapy.


Asunto(s)
Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Leucemia Mieloide/metabolismo , Enfermedad Aguda , Antígenos CD34/metabolismo , Apoptosis/efectos de los fármacos , Benzamidas/farmacología , Línea Celular Tumoral , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Citometría de Flujo , Humanos , Fosforilación , Recurrencia
20.
Biol Trace Elem Res ; 99(1-3): 211-7, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15235153

RESUMEN

In vitro and in vivo, mouse tissues assayed for 45Ca2+ uptake have shown that ATP increases the Ca2+ take-up in the presence of lactates of iron and aluminum, but this effect is absent with the citrates. The in vitro metal ion exchange with ATP has been demonstrated by electrophoresis and by chromatography. It is considered the cause of the increased capacity of ATP to modify the cellular effects of lactates. The in vitro modifications of Ca2+ uptake by lactates when in the presence of ATP are much more important than those of citrate. In general, aluminum compounds show a higher Ca2+ uptake and, coincidentally, they have shown a higher carcinogenic capacity than iron ATP.


Asunto(s)
Calcio/metabolismo , Metales/metabolismo , Adenosina Trifosfato/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Isótopos de Calcio , Iones/metabolismo , Ácido Láctico/farmacología , Radioisótopos , Ratas , Ratas Wistar
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