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1.
Phys Rev Lett ; 132(2): 021001, 2024 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-38277596

RESUMEN

We show, for the first time, radio measurements of the depth of shower maximum (X_{max}) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using measurements at the Pierre Auger Observatory we show full compatibility between our radio and the previously published fluorescence dataset, and between a subset of air showers observed simultaneously with both radio and fluorescence techniques, a measurement setup unique to the Pierre Auger Observatory. Furthermore, we show radio X_{max} resolution as a function of energy and demonstrate the ability to make competitive high-resolution X_{max} measurements with even a sparse radio array. With this, we show that the radio technique is capable of cosmic-ray mass composition studies, both at Auger and at other experiments.

2.
Phys Rev Lett ; 130(6): 061001, 2023 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-36827568

RESUMEN

Instantons, which are nonperturbative solutions to Yang-Mills equations, provide a signal for the occurrence of quantum tunneling between distinct classes of vacua. They can give rise to decays of particles otherwise forbidden. Using data collected at the Pierre Auger Observatory, we search for signatures of such instanton-induced processes that would be suggestive of super-heavy particles decaying in the Galactic halo. These particles could have been produced during the post-inflationary epoch and match the relic abundance of dark matter inferred today. The nonobservation of the signatures searched for allows us to derive a bound on the reduced coupling constant of gauge interactions in the dark sector: α_{X}≲0.09, for 10^{9}≲M_{X}/GeV<10^{19}. Conversely, we obtain that, for instance, a reduced coupling constant α_{X}=0.09 excludes masses M_{X}≳3×10^{13} GeV. In the context of dark matter production from gravitational interactions alone, we illustrate how these bounds are complementary to those obtained on the Hubble rate at the end of inflation from the nonobservation of tensor modes in the cosmological microwave background.

3.
Phys Rev Lett ; 126(15): 152002, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33929235

RESUMEN

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.

4.
Phys Rev Lett ; 126(14): 141301, 2021 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-33891448

RESUMEN

We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain Ω_{m}=0.305_{-0.038}^{+0.055} and σ_{8}=0.783_{-0.054}^{+0.064}. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys.

5.
Phys Rev Lett ; 125(12): 121106, 2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-33016715

RESUMEN

We report a measurement of the energy spectrum of cosmic rays above 2.5×10^{18} eV based on 215 030 events. New results are presented: at about 1.3×10^{19} eV, the spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving to 5.1±0.3(stat)±0.1(syst) beyond 5×10^{19} eV, while no significant dependence of spectral features on the declination is seen in the accessible range. These features of the spectrum can be reproduced in models with energy-dependent mass composition. The energy density in cosmic rays above 5×10^{18} eV is [5.66±0.03(stat)±1.40(syst)]×10^{53} erg Mpc^{-3}.

6.
Phys Rev Lett ; 122(17): 171301, 2019 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-31107093

RESUMEN

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

7.
Phys Rev Lett ; 116(24): 241101, 2016 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-27367377

RESUMEN

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

8.
Phys Rev Lett ; 117(19): 192001, 2016 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-27858429

RESUMEN

Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_{CM}=110-170 TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

9.
Handchir Mikrochir Plast Chir ; 40(2): 81-7, 2008 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-18437665

RESUMEN

PURPOSE: In spite of the high incidence of dermal fibroproliferative disorders, there is no agreement about the treatment of choice. Due to the inability of animals to produce keloid tissue, a standardised model to study the effects of different treatment modalities in vivo is lacking. Therefore, a comparative study on the effect of three pharmacological agents was conducted with human keloid implants in an athymic mouse model. MATERIAL AND METHODS: Cubic keloid tissue blocks from 10 human volunteers were implanted in 54 male, athymic, homozygotic mice. The animals were divided into 4 groups, including an untreated control group. Members of each section received either colchicine, nicardipine or triamcinolone applied transdermally into the keloid tissue or into the peritoneum. The tissue specimens of 5 mice each were explanted according to a predetermined time schedule on days 28, 42 and 56 post-implantation and examined using various histological techniques including standard dye and immune histochemistry. The freeze-dried and moist weights of the keloid tissue were determined and analysed. RESULTS: Statistically significant changes regarding declining weight parameters were seen in the colchicines-treated group. Moreover, the densities of fibroblasts and endothelial cells were significantly reduced through colchicines treatment when compared to the control group and the groups treated with the other agents. The triamcinolone group also showed partially significant changes of weight compared to the control group, whereas no statistically significant effect of nicardipine on any parameter was found. Any influence of the host organism could be excluded as there were no signs of rejection or lymphocytic infiltration. CONCLUSION: Our study represents a successful attempt to create a standardised model for a comparative investigation on keloid tissue in vivo. The effect of colchicine was demonstrated in the light of an inhibitory effect on fibroblastic proliferative activity. The studied model allows a direct comparison of implanted, vascularised keloid tissue and its reactivity to various agents without being biased by numerous unknown variables in humans.


Asunto(s)
Antiinflamatorios/uso terapéutico , Colchicina/uso terapéutico , Glucocorticoides/uso terapéutico , Queloide/tratamiento farmacológico , Nicardipino/uso terapéutico , Triamcinolona/uso terapéutico , Administración Cutánea , Animales , Antiinflamatorios/administración & dosificación , Colchicina/administración & dosificación , Interpretación Estadística de Datos , Modelos Animales de Enfermedad , Glucocorticoides/administración & dosificación , Técnicas Histológicas , Homocigoto , Humanos , Inmunohistoquímica , Inyecciones Intraperitoneales , Queloide/patología , Masculino , Ratones , Ratones Desnudos , Nicardipino/administración & dosificación , Trasplante de Piel , Factores de Tiempo , Trasplante Heterólogo , Triamcinolona/administración & dosificación
10.
Chirurg ; 78(4): 356-61, 2007 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-17226006

RESUMEN

BACKGROUND: Axillary hyperhidrosis is a dysfunction of the secretion of sweat glands. Conservative treatment modalities are mostly ineffective. Liposuction combined with subcutaneous curettage (TLC) destroys the sweat glands, while Botox injections inhibit the cholinergic transmission. MATERIAL AND METHOD: Of a total of 88 patients, TLC was carried out in 47 and 41 patients received intradermal Botox injections. The effect of both forms of treatment on the quality of life was assessed using a specific hyperhidrosis questionnaire and was correlated with sweat volumes measured by gravimetry. RESULTS: Follow-up after 6 months showed significantly changed sweat volumes of 52+/-41 mg/min of TLC patients versus 78+/-87 mg/min in the Botox group. In the TLC group 91% and in the Botox group 98% were satisfied with the result. CONCLUSION: The stress of a single surgical intervention is to be weighed against the necessary repetitive application of multiple Botox injections. Both methods are superior to other, more radical surgical methods in terms of efficacy and complication rates. Botox and TLC lead to a significant improvement of the quality of life.


Asunto(s)
Axila , Toxinas Botulínicas Tipo A/uso terapéutico , Legrado/métodos , Hiperhidrosis/terapia , Lipectomía/métodos , Adolescente , Adulto , Axila/cirugía , Femenino , Estudios de Seguimiento , Humanos , Inyecciones Intradérmicas , Masculino , Satisfacción del Paciente , Estudios Prospectivos , Calidad de Vida/psicología , Retratamiento , Encuestas y Cuestionarios
11.
Infect Control Hosp Epidemiol ; 11(9): 479-85, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2230051

RESUMEN

Methicillin-resistant Staphylococcus aureus (MRSA) has been an endemic nosocomial pathogen at the VA medical center (VAMC) in Providence, Rhode Island since 1981. From 1985 to 1987, more than 30% of all unique S aureus isolates were methicillin resistant. To evaluate the frequency of acquisition of MRSA isolates by healthcare workers, we compared the antimicrobial susceptibility patterns, multilocus enzyme genotypes and plasmid profiles of isolates recovered from nasal and hand cultures from VAMC nurses and house staff on rotation at the VAMC with those of clinical isolates from patients at the VAMC and four other affiliated hospitals. Fifty-six percent of ward nurses cultured (n = 112) were colonized with S aureus, of which 65% was methicillin resistant. Six isolates of MRSA were identified on the initial culturing of house staff (n = 65); 16 MRSA isolates were recovered at the end of a four-week rotation (p less than .02). Phenotypic and genotypic analyses demonstrated that numerous distinct MRSA strains were recovered in the study period. The incidence of MRSA among clinical isolates at the VAMC and affiliated institutions was remarkably constant throughout the three-year study period. Moreover, despite regularly sharing resident physicians, interns and medical students, MRSA isolates were commonly recovered at the other university-affiliated hospitals. Our study failed to reveal evidence of significant interhospital transmission of MRSA isolates by healthcare workers. While healthcare workers may contribute to the dissemination of MRSA within institutions, they appear to be less important in spreading MRSA between institutions.


Asunto(s)
Personal de Hospital , Staphylococcus aureus/aislamiento & purificación , ADN Bacteriano/efectos de los fármacos , Farmacorresistencia Microbiana , Electroforesis en Gel de Almidón , Femenino , Genotipo , Mano/microbiología , Hospitales de Veteranos/estadística & datos numéricos , Humanos , Masculino , Meticilina/farmacología , Pruebas de Sensibilidad Microbiana , Nariz/microbiología , Plásmidos , Rhode Island , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/enzimología , Staphylococcus aureus/genética
12.
Cancer Genet Cytogenet ; 123(2): 114-22, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11156736

RESUMEN

We used comparative genomic hybridization (CGH) and conventional cytogenetics (CC) to define chromosomal changes and to evaluate the usefulness of CGH in 65 patients having childhood acute lymphoblastic leukemia (ALL). Subsequently, fluorescence in situ hybridization (FISH) was used to evaluate the CGH and cytogenetic results. Comparative genomic hybridization revealed DNA copy number changes in 49 (75%) patients (including 7 patients with unsuccessful cytogenetics and 2 patients with normal karyotype). A total of 85 losses and 195 gains were detected. The most commonly gained chromosomes were 21 (35%), X (31%), 18 (27%), 10 (26%), 6 (25%), 17 (25%), 4 (23%), and 14 (22%). Losses were most frequently observed on chromosomes 9p (18%) and 12p (11%). Other losses were detected on chromosomes 13q (9%), 6q (9%), 7p (8%), and chromosome X (6%). Conventional cytogenetics revealed chromosomal changes in 53 (82%) patients. The employment of CGH and FISH together with CC analysis revealed chromosomal changes in 62 (95%) of the childhood ALL patients investigated. The CGH completed CC results in 36 patients; in 9 patients, the changes escaped detection without using CGH. The results of our study were compared to 6 other CGH studies previously reported. Our observations underline the benefits of supplementing routine cytogenetic investigation in childhood ALL by FISH and CGH, because small unbalanced changes may escape detection when conventional cytogenetics is the only diagnostic method used.


Asunto(s)
Aberraciones Cromosómicas , Hibridación de Ácido Nucleico/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Niño , Preescolar , Bandeo Cromosómico , Análisis Citogenético , Femenino , Humanos , Hibridación Fluorescente in Situ , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología
13.
J La State Med Soc ; 149(6): 234-8, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9231625

RESUMEN

At the Ochsner Clinic we recently performed our 250th liver transplant. Reaching this milestone has led us to reflect back on the history of liver transplant, both at our own institution and nationally, noting the many achievements and improvements in liver transplantation during the relatively brief history of this therapeutic modality. Furthermore, there are a number of issues both medical and political which will likely be affecting how liver transplantation is performed in the future.


Asunto(s)
Hepatopatías/cirugía , Trasplante de Hígado , Enfermedad Crónica , Humanos , Trasplante de Hígado/métodos , Trasplante de Hígado/tendencias , Louisiana , Preservación de Órganos/métodos
14.
Cesk Patol ; 15(1): 41-8, 1979 Feb.
Artículo en Checo | MEDLINE | ID: mdl-35284

RESUMEN

Intraperitoneal application of 0.7 microgram S III pneumococcal polysaccharide led to a significant increase in the values of nucleolar activation in small, medium, and large lymphocytes, plasmoblasts, and plasmatic cells in a white mouse. Macrophages did not respond to the application of S III by an increase in nucleolar activation. The study tested the possibility of using the observation of the functional morphology of the nucleous for observing the changes in the activation of B-cells after administration of nonspecific mitogen and a thymus-independent antigen.


Asunto(s)
Nucléolo Celular/ultraestructura , Activación de Linfocitos/efectos de los fármacos , Polisacáridos Bacterianos/farmacología , Animales , Linfocitos/ultraestructura , Ratones , Streptococcus pneumoniae
15.
Cesk Patol ; 12(2): 89-103, 1976 May.
Artículo en Checo | MEDLINE | ID: mdl-1009619

RESUMEN

The course of immunocytoadherence was followed in the mouse spleen during the primary immune response to intraperitoneal administration of sheep red blood cells at 24 hours, 72 hours and 6 days following a total body iradiation with a dose of 450 r after antigen administration. The number of RFC becomes reduced immediately after irradiation. The reduction thereof always correlates with a relative increase of macrophages. Small and medium-sized lymphocytes rapidly disappear from the population of rosette-forming cells. If the irradiation had been carried out before the radiation-uninfluenced reaction reached its maximum, the large lymphocytes relatively increase in number. In other cases their immunocytoadherent activity also shows a steadily decreasing tendency. During the primary reaction, irradiation always increases the total relative plasma cell count as related to the other RFC. In such cases the propurtion of the mature forms is larger than of the blastic ones. The values observer at the end of the studied postirradiation period in the sourse of the primary reaction are always characterized by a higher proportion of the plasma cell line at about 20 - 25.


Asunto(s)
Formación de Anticuerpos/efectos de la radiación , Antígenos/administración & dosificación , Reacción de Inmunoadherencia , Bazo/inmunología , Animales , Movimiento Celular , Linfocitos/inmunología , Macrófagos/inmunología , Ratones , Ovinos , Factores de Tiempo
16.
Cesk Patol ; 12(2): 83-8, 1976 May.
Artículo en Checo | MEDLINE | ID: mdl-1087582

RESUMEN

The course of spontaneous immunocytoadherence as influenced by a total body 850 r irradiation was studied in the mouse spleen. Prior to the total body irradiation 0.87 RFC/100 cells occurring spontaneously, without any previous antigenic stimulus, were dislosed in the spleen. Twenty four hours after iraadiation 0.075 RFC/1000 cells were detected. This number dropped to 0.023 RFC/1000 cells at day 4 after irradiation. A qualitative morphological analysis showed the following values: 65,1% of the spontaneous RFC were small lymphocytes, 24.5% were medium-sized lymphocytes and 3% large lymphocytes; 1.1% were plasma cells and 5.4% macrophages. Twenty four hours after irradiation with a dose of 850 r the RFC contained 9.3% plasma cells, and 90.7% macrophages, the respective numbers on day 2 being 7.5% and 98.3%. At day 4, permitting to demonstrate the RFC in significant numbers there occurred macrophages only. The model experiment has shown that the formation of spontaneous rosettes represents a cirtually normal immune reaction.


Asunto(s)
Formación de Anticuerpos/efectos de la radiación , Reacción de Inmunoadherencia , Bazo/inmunología , Animales , Movimiento Celular , Ratones , Dosis de Radiación , Linfocitos T/inmunología
17.
Cesk Patol ; 13(1-2): 52-63, 1977 May.
Artículo en Checo | MEDLINE | ID: mdl-74293

RESUMEN

During the primary immune response induced by the administration of sheep erythrocytes in mice, nucleolar activation was observed in macrophages, lymphocytes as well as in plasmacytes. The first maximum (4.6%) was observed on day 3 in macrophagic cells. Maximal activation of plasmoblasts (6.6%) and plasmacytes (5.9%) was observed on day the lymphoid series the first maximum in the occurrence of cells showing specific immunological activatin was as follows: large lymphocytes on day (6.5%), medium-sized lymphocytes on day 7 (6.6%) and, ultimately, small lymphocytes (6.3%) on day 8. The study verified the possibility of using nucleolar staining for estimating its functional morphology and thus following the changes of specific immunological activation during the primary immunological response.


Asunto(s)
Formación de Anticuerpos , Nucléolo Celular/inmunología , Inmunidad , Animales , Eritrocitos/inmunología , Linfocitos/inmunología , Macrófagos/inmunología , Ratones , Células Plasmáticas/inmunología , Ovinos , Bazo/inmunología , Coloración y Etiquetado
18.
Cesk Patol ; 12(4): 209-20, 1976 Nov.
Artículo en Checo | MEDLINE | ID: mdl-1031649

RESUMEN

Observations were made of the course of secondary immunological response, using the immuno-cyto-adherence method under the influence of 450 r general body irradiation on murine spleen following secondary ram erythrocyte immunization. Irradiation was applied 24 hours, 72 hours and 6 days after an i.p. administration of antigen. Irradiation was immediately followed by an absolute as well as relative drop in RFC number and by an overall drop in splenic cell number. In case of irradiation applied prior to reaching the secondary reaction quantitative maximum, there was a development of the increment and another RFC quantitative maximum was reached between days 15--20 after irradiation. Small and medium size lymphocyte values were seen decreasing immediately after irradiation. Where irradiation took place prior to reaching the quantitative maximum of a normally proceeding anamnestic reaction, large lymphocytes constituting RFC were increasingly represented after a certain period of stagnation or even without it. Plasmatic series cells on irradiation tended to increase their total share to become a prominent cell element after delayed quantitative RFC maxima had been reached and to reach complete predominance towards the end of the period of time under observation. A relative increase in the proportion of macrophages was seen immediately after irradiation.


Asunto(s)
Formación de Anticuerpos/efectos de la radiación , Antígenos/administración & dosificación , Reacción de Inmunoadherencia , Bazo/inmunología , Animales , Linfocitos/inmunología , Ratones , Bazo/citología , Factores de Tiempo
19.
Ophthalmologe ; 110(11): 1058-62, 2013 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-23595652

RESUMEN

BACKGROUND: The aim of the study was a clinical evaluation of an intraocular lens (IOL) with a segmental multifocal optic design and near addition of + 3.0 D as part of a CE approval study. PATIENTS AND METHODS: In a multicenter study the LENTIS Mplus LS-312 MF IOL (Oculentis) was implanted in 134 eyes of 79 patients with a mean age of 68 ± 12 years. The multifocality is achieved by implementation of a distance part and a segmented near sector. Three months after surgery, uncorrected and best corrected distance visual acuity (UCDVA and BCDVA, respectively), near visual acuity (UCNVA and BCNVA, respectively), contrast vision and patient satisfaction (questionnaire) were evaluated. RESULTS: The IOLs were implanted uneventfully either unilaterally or bilaterally and 3 months postoperatively (n = 86 eyes) the following mean visual acuities were obtained (logMAR): UCDVA = 0.05, BCDVA = - 0.01, UCNVA = 0.09 and BCNVA = 0.02. Contrast sensitivity (n = 25 eyes) was within normal limits. Of the 66 questioned patients 10.6% spontaneously reported halos and 3% glare. CONCLUSION: This new innovative multifocal IOL concept showed very good functional results as well as high patient satisfaction.


Asunto(s)
Implantación de Lentes Intraoculares/estadística & datos numéricos , Lentes Intraoculares/estadística & datos numéricos , Errores de Refracción/diagnóstico , Errores de Refracción/epidemiología , Trastornos de la Visión/epidemiología , Trastornos de la Visión/cirugía , Adulto , Anciano , Análisis de Falla de Equipo , Femenino , Alemania/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente/estadística & datos numéricos , Prevalencia , Diseño de Prótesis , Resultado del Tratamiento , Trastornos de la Visión/diagnóstico , Adulto Joven
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