Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
1.
Nature ; 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38720083

RESUMEN

A new class of superfluids and superconductors with spatially periodic modulation of the superfluid density is arising1-12. It might be related to the supersolid phase of matter, in which the spontaneous breaking of gauge and translational symmetries leads to a spatially modulated macroscopic wavefunction13-16. This relation was recognized only in some cases1,2,5-9 and there is the need for a universal property quantifying the differences between supersolids and ordinary matter, such as the superfluid fraction, which measures the reduction in superfluid stiffness resulting from the spatial modulation16-18. The superfluid fraction was introduced long ago16, but it has not yet been assessed experimentally. Here we demonstrate an innovative method to measure the superfluid fraction based on the Josephson effect, a ubiquitous phenomenon associated with the presence of a physical barrier between two superfluids or superconductors19, which might also be expected for supersolids20, owing to the spatial modulation. We demonstrate that individual cells of a supersolid can sustain Josephson oscillations and we show that, from the current-phase dynamics, we can derive directly the superfluid fraction. Our study of a cold-atom dipolar supersolid7 reveals a relatively large sub-unity superfluid fraction that makes realistic the study of previously unknown phenomena such as partially quantized vortices and supercurrents16-18. Our results open a new direction of research that may unify the description of all supersolid-like systems.

2.
Med Klin Intensivmed Notfmed ; 117(2): 120-128, 2022 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-33481077

RESUMEN

BACKGROUND: There is currently no reliable method to identify which COVID-19 patients in the emergency department will experience rapid disease progression and death. AIM: The aim of this work is to investigate predictive risk factors for 30-day mortality in COVID-19 (coronavirus disease 2019) patients with interstitial pneumonia using patient history, and clinical and laboratory parameters and to develop a nomogram for risk stratification in the emergency department. METHODS: A retrospective, multicenter study was conducted in a cohort of 164 patients with COVID-19 pneumonia in the emergency departments of hospitals in Merano and Bressanone from 1 March 2020 to 31 March 2020. Patients were diagnosed as positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using fluorescence reverse transcription polymerase chain reaction (RT-PCR). A nomogram for risk stratification of 30-day mortality of COVID-19 patients was developed based on the parameters studied. RESULTS: In all, 35 (21.3%) of 164 COVID-19 patients with interstitial pneumonia died within 30 days of admission to the emergency department. Multivariate analysis method revealed that cognitive deterioration (odds ratio [OR]: 8.330; p = 0.004), lymphocytopenia (OR: 4.229; p = 0.049), renal function deterioration (OR: 4.841; p = 0.028), peripheral oxygen saturation < 93% (OR: 17.871; p = 0.002), age > 75 years (OR: 2.925; p = 0.032), elevated C­reactive protein (OR: 6.504; p = 0.005), low monocyte count (OR: 0.504; p = 0.004), and comorbidity (OR 5.862; p = 0.019) were associated with 30-day mortality. Using these eight parameters, a nomogram was developed that showed good discrimination with an area under the ROC curve of 0.937. CONCLUSION: The initial evaluation of the patient history, and the clinical and laboratory data collected in the emergency department provides important prognostic information for risk stratification of COVID-19 patients in the emergency department and for early identification of patients with risk for critical disease course.


Asunto(s)
COVID-19 , Enfermedades Pulmonares Intersticiales , Anciano , COVID-19/diagnóstico , Servicio de Urgencia en Hospital , Humanos , Nomogramas , Estudios Retrospectivos , Medición de Riesgo , SARS-CoV-2
3.
Science ; 371(6534): 1162-1165, 2021 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-33602866

RESUMEN

A key manifestation of superfluidity in liquids and gases is a reduction of the moment of inertia under slow rotations. Nonclassical rotational effects have also been considered in the context of the elusive supersolid phase of matter, in which superfluidity coexists with a lattice structure. Here, we show that the recently discovered supersolid phase in dipolar quantum gases features a reduced moment of inertia. Using a dipolar gas of dysprosium atoms, we studied a peculiar rotational oscillation mode in a harmonic potential, the scissors mode, previously investigated in ordinary superfluids. From the measured moment of inertia, we deduced a superfluid fraction that is different from zero and of order of unity, providing direct evidence of the superfluid nature of the dipolar supersolid.

4.
Vet Microbiol ; 251: 108910, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33160194

RESUMEN

Mycoplasma haemocanis (Mhc) and "Candidatus Mycoplasma haematoparvum" (CMhp) are the main haemoplasma species known to infect dogs. The aim of this study was to determine the prevalence of haemoplasma species infections in hunting dogs from southern Italy and assess related risk factors. 1,433 hunting dogs living in Campania region were tested by qPCR assay. The prevalence was 19.9 %; 13.1 % for Mhc and 11.4 % for CMhp; 4.6 % showed a coinfection with both haemoplasma species. Statistical analysis revealed living in Salerno province (Mhc: OR 3.72; CMhp: OR 2.74), hound (Mhc: OR 5.26; CMhp: OR 8.46) and mixed breed (Mhc: OR 3.38; CMhp: OR 2.80), rural environment (Mhc: OR 12.58; CMhp: OR 10.38), wild mammal hunting (Mhc: OR 8.73; CMhp: OR 8.32), cohabitation with other animals (Mhc: OR 2.82; CMhp: OR 2.78) and large pack size (Mhc: OR 2.96; CMhp: OR 1.61) as risk factors for haemoplasmas. Male gender (OR 1.44) and tick infestation history (OR 1.40) represented risk factors only for Mhc, while adult age (2-7 years - OR 2.01; > 7 years - OR 1.84) and large body size (OR 1.48) were associated only to CMhp. Mhc infection was significantly associated to Babesia vogeli (p < 0.05) and Hepatozoon canis (p < 0.001), while CMhp with H. canis (p < 0.001). This study adds information on haemoplasma species distribution in hunting dogs in southern Italy. Outdoor lifestyle and contact with wild fauna, through greater exposure to tick infestation, or possibly wounds acquired during hunting or fighting, could be factors contributing to haemoplasma infections.


Asunto(s)
Enfermedades de los Perros/epidemiología , Infecciones por Mycoplasma/epidemiología , Infecciones por Mycoplasma/veterinaria , Mycoplasma/genética , Mycoplasma/aislamiento & purificación , Infestaciones por Garrapatas/veterinaria , Perros de Trabajo/microbiología , Animales , ADN Bacteriano/genética , Enfermedades de los Perros/microbiología , Perros , Femenino , Italia/epidemiología , Masculino , Mycoplasma/clasificación , Mycoplasma/patogenicidad , Prevalencia , ARN Ribosómico 16S/genética , Factores de Riesgo
5.
Parasitol Res ; 119(9): 3023-3031, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32725320

RESUMEN

Hepatozoon canis is a hemoprotozoan organism that infects domestic and wild carnivores throughout much of Europe. The parasite is mainly transmitted through the ingestion of infected ticks containing mature oocysts. The aims of the present survey were to determine the prevalence of H. canis in hunting dogs living in Southern Italy and to assess potential infection risk factors. DNA extracted from whole blood samples, collected from 1433 apparently healthy dogs living in the Napoli, Avellino, and Salerno provinces of Campania region (Southern Italy), was tested by a quantitative real-time polymerase chain reaction (qPCR) assay to amplify H. canis. Furthermore, the investigated dog population was also screened by qPCR for the presence of Ehrlichia canis, a major tick-borne pathogen in Southern Italy, in order to assess possible co-infections. Two hundred dogs were H. canis PCR-positive, resulting in an overall prevalence of 14.0% (CI 12.2-15.9). Breed category (P < 0.0001), hair coat length (P = 0.015), and province of residence (P < 0.0001) represented significant risk factors for H. canis infection. The presence of H. canis DNA was also significantly associated with E. canis PCR positivity (P < 0.0001). Hunting dogs in Campania region (Southern Italy) are frequently exposed to H. canis, and the infection is potentially associated with close contact with wildlife. Further studies are needed to assess the pathogenic potential of H. canis, as well as the epidemiological relationships between hunting dogs and wild animal populations sharing the same habitats in Southern Italy.


Asunto(s)
Coccidiosis/veterinaria , Enfermedades de los Perros/parasitología , Eucoccidiida/aislamiento & purificación , Animales , Coccidiosis/parasitología , Coccidiosis/transmisión , Enfermedades de los Perros/sangre , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/transmisión , Perros , Eucoccidiida/genética , Eucoccidiida/fisiología , Femenino , Italia/epidemiología , Masculino , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Garrapatas/parasitología , Garrapatas/fisiología
6.
Lett Appl Microbiol ; 69(6): 399-402, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31618795

RESUMEN

The sugar glider (Petaurus breviceps) is a small, arboreal, nocturnal, gliding mammalian possum belonging to the marsupial infraclass. Exotic marsupials, including sugar gliders, are becoming popular companion pets and, consequently, the risk of potential infections that can be transmitted to humans should be investigated. Data on the role of the sugar glider as a possible carrier of pathogenic and zoonotic bacteria are scarce and fragmentary. Therefore, this study is aimed at evaluating the prevalence of potentially zoonotic bacteria (Salmonella spp., Escherichia coli, Campylobacter spp., Pseudomonas spp., Klebsiella spp., Listeria monocytogenes and Yersinia enterocolitica) in 64 sugar gliders kept as pets in Italy. The highest prevalence of infection pertained to members of the family Enterobacteriaceae, in particular Citrobacter spp. (50%), Enterobacter spp. (28·1%) and Klebsiella pneumoniae (15·6%); Pseudomonas aeruginosa was isolated from 10 out of 64 samples (15·6%). All strains of Klebsiella pneumoniae exhibited some level of resistance to multiple antimicrobials (ampicillin, amoxicillin-clavulanic acid and doxycycline). SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study show that sugar gliders may act as carriers of potentially pathogenic agents for humans and other animal species, therefore caution should be exercised in the handling and contact with these animals.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/fisiología , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/aislamiento & purificación , Marsupiales/microbiología , Mascotas/microbiología , Animales , Enterobacteriaceae/clasificación , Italia
7.
Nature ; 574(7778): 382-385, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31499510

RESUMEN

Supersolids are exotic materials combining the frictionless flow of a superfluid with the crystal-like periodic density modulation of a solid. The supersolid phase of matter was predicted 50 years ago1-3 for solid helium4-8. Ultracold quantum gases have recently been made to exhibit periodic order typical of a crystal, owing to various types of controllable interaction9-13. A crucial feature of a D-dimensional supersolid is the occurrence of D + 1 gapless excitations, reflecting the Goldstone modes associated with the spontaneous breaking of two continuous symmetries: the breaking of phase invariance, corresponding to the locking of the phase of the atomic wave functions at the origin of superfluid phenomena, and the breaking of translational invariance due to the lattice structure of the system. Such modes have been the object of intense theoretical investigations1,14-18, but they have not yet been observed experimentally. Here we demonstrate supersolid symmetry breaking through the appearance of two distinct compressional oscillation modes in a harmonically trapped dipolar Bose-Einstein condensate, reflecting the gapless Goldstone excitations of the homogeneous system. We observe that the higher-frequency mode is associated with an oscillation of the periodicity of the emergent lattice and the lower-frequency mode characterizes the superfluid oscillations. This work also suggests the presence of two separate quantum phase transitions between the superfluid, supersolid and solid-like configurations.

9.
Phys Rev Lett ; 122(13): 130405, 2019 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-31012602

RESUMEN

The competition of dipole-dipole and contact interactions leads to exciting new physics in dipolar gases, well illustrated by the recent observation of quantum droplets and rotons in dipolar condensates. We show that the combination of the roton instability and quantum stabilization leads under proper conditions to a novel regime that presents supersolid properties due to the coexistence of stripe modulation and phase coherence. In a combined experimental and theoretical analysis, we determine the parameter regime for the formation of coherent stripes, whose lifetime of a few tens of milliseconds is limited by the eventual destruction of the stripe pattern due to three-body losses. Our results open intriguing prospects for the development of long-lived dipolar supersolids.

10.
J Small Anim Pract ; 59(5): 294-297, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29315571

RESUMEN

OBJECTIVES: Reptiles are considered an important reservoir of Salmonella species. This study evaluated the prevalence of Salmonella species in different species of gecko kept as pets in Italy. MATERIALS AND METHODS: Faecal swab samples were collected from 70 clinically healthy geckos and examined for Salmonella species by culture that were then serotyped. RESULTS: Salmonella species were isolated from 24 of 70 (34·3%) samples. Eighteen isolates expressed resistance to ceftazidime and four isolates to ampicillin. CLINICAL SIGNIFICANCE: Salmonella spp. can be isolated from apparently healthy captive gecko which should be considered as a potential source of infection for humans and other companion animals.


Asunto(s)
Lagartos/microbiología , Salmonella/aislamiento & purificación , Animales , Farmacorresistencia Bacteriana , Heces/microbiología , Italia/epidemiología , Mascotas/microbiología , Salmonella/clasificación , Salmonelosis Animal/microbiología , Serotipificación
11.
Lett Appl Microbiol ; 66(3): 202-206, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29250802

RESUMEN

The importance of wild birds as potential vectors of disease has received recent renewed empirical interest, especially regarding human health although information regarding the enteropathogenic bacteria in birds of prey continue to be scant. This study was performed with the aim to evaluate the occurrence of enteropathogenic bacteria (i.e. Campylobacter spp. Escherichia coli, Salmonella spp.) in birds of prey carcasses in Southern Italy. The results of the present study showed a prevalence of 33·1% (49/148) for Campylobacter spp. where all positive isolates (49/49) were identified as Campylobacter jejuni, and among these positive 12/49 were also identified as Campylobacter coli. Thus, 12/49 birds of prey showed mixed infections for both Campylobacter species. Differences in Campylobacter spp. prevalence between diurnal and nocturnal birds were statistically significant (P = 0·016). Escherichia coli showed a prevalence of 6·8% (10/148) and were serogrouped as O26 (n = 3), O55 (n = 2), O145 (n = 5). Salmonella spp. showed a prevalence of 6·8% (10/148) and were serotyped as S. Napoli (n = 4), Salmonella salamae (n = 3) and S. Typhimurium (n = 3). Although wildlife disease outbreaks have often been underreported in the broader context of global epidemiology, results of the present study suggest that birds of prey may serve as a reservoir of pathogens for livestock and human health, acting at the animal-human-ecosystem interface. SIGNIFICANCE AND IMPACT OF THE STUDY: This study confirms the role of birds of prey as a reservoir of enteropathogenic bacteria (i.e. Campylobacter spp., Escherichia coli, Salmonella spp.). Wild birds can contaminate environment with their faeces and play a crucial role in the transmission of pathogens to poultry and livestock farms and aquifers supplying water to humans. Furthermore, wild birds could disseminate pathogens within rescue and rehabilitation centres where they are admitted.


Asunto(s)
Infecciones por Campylobacter/epidemiología , Campylobacter jejuni/aislamiento & purificación , Reservorios de Enfermedades/microbiología , Infecciones por Escherichia coli/epidemiología , Escherichia coli/aislamiento & purificación , Rapaces/microbiología , Salmonelosis Animal/epidemiología , Salmonella/aislamiento & purificación , Animales , Animales Salvajes/microbiología , Aves , Infecciones por Campylobacter/microbiología , Infecciones por Campylobacter/veterinaria , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/veterinaria , Granjas , Heces/microbiología , Humanos , Italia/epidemiología , Ganado/microbiología , Prevalencia , Salmonella/clasificación , Salmonelosis Animal/microbiología
12.
Ultramicroscopy ; 164: 70-7, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26876642

RESUMEN

We demonstrate a prototype of a Focused Ion Beam machine based on the ionization of a laser-cooled cesium beam and adapted for imaging and modifying different surfaces in the few-tens nanometer range. Efficient atomic ionization is obtained by laser promoting ground-state atoms into a target excited Rydberg state, then field-ionizing them in an electric field gradient. The method allows obtaining ion currents up to 130pA. Comparison with the standard direct photo-ionization of the atomic beam shows, in our conditions, a 40-times larger ion yield. Preliminary imaging results at ion energies in the 1-5keV range are obtained with a resolution around 40nm, in the present version of the prototype. Our ion beam is expected to be extremely monochromatic, with an energy spread of the order of the eV, offering great prospects for lithography, imaging and surface analysis.

13.
Oral Implantol (Rome) ; 9(Suppl 1/2016 to N 4/2016): 38-44, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28280531

RESUMEN

OBJECTIVE: The aim of this prospective pilot clinical case series report was to evaluate, through a clinical and radiographic analysis, the peri-implant bone resorption of the tantalum dental implants (TMT) (Zimmer TMT, Parsippany, NJ, USA) one year after prosthetic rehabilitation. METHODS: Twenty tantalum dental implants were placed in both maxillas and mandibles of 20 patients. Patients were asked to attend a radiographic and clinical follow-up and their previous clinical records and X-rays were assessed. Bone levels were calculated by digitally measuring the distance from the implant shoulder to the first bone-to-implant on periapical radiographs taken at surgery and after 6 and 12 months of functioning. The Pearson correlation analysis was performed to assess it there was a correlation between the measurement of the marginal bone loss (MBL). The Anova Test with a post-hoc analysis using Bonferroni's test was used to compare the three group (0, 6 months and 12 months). RESULTS: The mean total MBL for the group 0 months was 0.84 mm (SD 0.21), 6 months was 0.87 mm (SD 0.22) and for 12 months was 0.89 mm (SD 0.23). The values of the Pearson's coefficients showed that the data measurement were positively correlated. The Anova test showed a statistically significant difference between the groups. CONCLUSION: The statistically significant difference in marginal bone loss can be considered physiological. Within the limits of this study it can be concluded that TMT implants have an excellent bone crest's stability, however, to have most accurate information, will be necessary extend the sample.

14.
Acta Otorhinolaryngol Ital ; 35(2): 110-5, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26019395

RESUMEN

The present study aims to evaluate and validate the Italian version of Khalfa's questionnaire on hyperacusis (HQ). We recruited 117 patients (64 men, 53 women, mean age 53 years, range 14-88) with tinnitus for at least 3 months as a primary disorder. All patients completed the THI and the Italian version of the HQ and underwent audiometry, pitch and loudness tinnitus matching, otoacoustic emissions with distortion products (DPOAE) and uncomfortable loudness level (ULL). The overall performance of the tests was evaluated and compared using the area under the RO C curve (AUC) relative to the tests. The cut-off of the HQ was calculated. We also assessed the Cronbach's alpha (αC) for the HQ and its three major dimensions (attentional - αC1, emotional - αC2 and social - αC3). Statistical analysis showed no correlation between DPOAE, audiometry, ULL and gender. We observed a high correlation (p < 0.05) between hyperacusis and ULL described by the Spearman's ρ index (rs = 0.72). We found a cut-off of 16 indicative of hyperacusis comparing the area under the RO C curve (AUC) of HQ and audiometry, taken as a diagnostic reference, (sensitivity = 67.9% and specificity = 72.2%). The reliability of HQ was confirmed by a high αC = 0.89. The αC for the single dimensional scales were, respectively, αC1 = 0.73, αC2 = 0.72 and αC3 = 0.81. The Italian version of the HQ is recommended for proper and complete classification of patients with tinnitus and hyperacusis. From our study, we found a cut-off of 16 instead of the cut-off of 28 described as very high by other authors. Moreover, ULL was an important variable and can be discriminating in the evaluation of hyperacusis.


Asunto(s)
Hiperacusia/diagnóstico , Autoinforme , Acúfeno/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Italia , Lenguaje , Masculino , Persona de Mediana Edad , Adulto Joven
15.
Lett Appl Microbiol ; 58(5): 462-5, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24383854

RESUMEN

UNLABELLED: This study was aimed at evaluating the oral bacterial flora of 60 Python regius kept as pets by culture and biochemical methods. All isolates were also submitted to antimicrobial susceptibility testing using the disc diffusion method. The oral cavity of snakes sampled harboured a wide range of Gram-negative bacteria mainly constituted by Pseudomonas spp., Morganella morganii, Acinetobacter calcoaceticus, Aeromonas hydrophila, but also by Salmonella spp. Staphylococcus spp. was the commonest Gram-positive isolates, and various anaerobic Clostridium species were also found. The most effective antimicrobial agents were enrofloxacin and ciprofloxacin, followed by doxycycline and gentamicin. SIGNIFICANCE AND IMPACT OF THE STUDY: The oral cavity of snakes sampled harboured a wide range of bacteria. Our results suggest that people who come in contact with snakes could be at risk of infection and should follow proper hygiene practices when handling these reptiles.


Asunto(s)
Antibacterianos/farmacología , Boidae/microbiología , Clostridium/aislamiento & purificación , Bacterias Gramnegativas/aislamiento & purificación , Orofaringe/microbiología , Mascotas , Staphylococcus/aislamiento & purificación , Animales , Clostridium/clasificación , Femenino , Bacterias Gramnegativas/clasificación , Bacterias Gramnegativas/efectos de los fármacos , Humanos , Italia , Masculino , Zoonosis/microbiología
16.
Vet J ; 197(3): 884-5, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23680265

RESUMEN

This research investigated the prevalence of gastrointestinal (GI) strongyles and Escherichia coli O157 in naturally infected sheep, as well as the possible correlation between the pathogens examined. A total of 314 sheep, randomly selected from 21 farms located in southern Italy, were examined. GI strongyles and E. coli O157 were detected by using the FLOTAC double technique and culture media, respectively. GI strongyles were detected on 19/21 farms (90.5%) and E. coli O157 on 12/21 (57.4%). At the animal level, GI strongyles were detected from 193/314 (61.5%) sheep analysed, whereas E. coli O157 was isolated from 20/314 (6.4%) sheep. Statistical analysis performed at animal-level showed a negative correlation between E. coli O157 and GI strongyle EPGs (Spearman's ρ=-0.128; P=0.03). Caution should be exercised in interpreting the research findings because a number of different confounding factors possibly influenced the trend of negative correlation between the two pathogenic agents investigated. Further studies, including molecular diagnostics, production data and multivariable analytical approaches, are needed to assess the actual impact of multiple pathogen infections in grazing sheep and other livestock species.


Asunto(s)
Coinfección/veterinaria , Infecciones por Escherichia coli/veterinaria , Escherichia coli O157/aislamiento & purificación , Enfermedades de las Ovejas/etiología , Infecciones por Strongylida/veterinaria , Estrongílidos/clasificación , Animales , Infecciones por Escherichia coli/complicaciones , Infecciones por Escherichia coli/microbiología , Enfermedades Gastrointestinales/microbiología , Enfermedades Gastrointestinales/parasitología , Enfermedades Gastrointestinales/veterinaria , Ovinos , Enfermedades de las Ovejas/microbiología , Enfermedades de las Ovejas/parasitología , Infecciones por Strongylida/complicaciones , Infecciones por Strongylida/parasitología
17.
Phys Rev Lett ; 109(18): 183001, 2012 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-23215275

RESUMEN

We demonstrate rotational and vibrational cooling of cesium dimers by optical pumping techniques. We use two laser sources exciting all the populated rovibrational states, except a target state that thus behaves like a dark state where molecules pile up thanks to absorption-spontaneous emission cycles. We are able to accumulate photoassociated cold Cs(2) molecules in their absolute ground state (v = 0, J = 0) with up to 40% efficiency. Given its simplicity, the method could be extended to other molecules and molecular beams. It also opens up general perspectives in laser cooling the external degrees of freedom of molecules.

18.
Phys Rev Lett ; 108(2): 023005, 2012 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-22324680

RESUMEN

Cold Rydberg atoms subject to long-range dipole-dipole interactions represent a particularly interesting system for exploring few-body interactions and probing the transition from 2-body physics to the many-body regime. In this work we report the direct observation of a resonant 4-body Rydberg interaction. We exploit the occurrence of an accidental quasicoincidence of a 2-body and a 4-body resonant Stark-tuned Förster process in cesium to observe a resonant energy transfer requiring the simultaneous interaction of at least four neighboring atoms. These results are relevant for the implementation of quantum gates with Rydberg atoms and for further studies of many-body physics.

19.
Acta Otorhinolaryngol Ital ; 32(5): 320-5, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23326012

RESUMEN

The purpose of this study was to evaluate the correlation between severity of obstructive sleep apnoea syndrome (OSAS), cardiovascular disease and metabolic syndrome. We recruited 1185 patients with OSAS who underwent a complete ENT examination, including nasolaryngeal fibre optic endoscopy with Müller's manoeuvre, overnight cardio-respiratory monitoring, Epworth Sleepiness Scale (ESS) to measure daytime sleepiness, body mass index (BMI), measurement of blood pressure and blood tests.SUBSEQUENTLY, SUBJECTS WERE DIVIDED INTO THREE SUBGROUPS ACCORDING TO THE APNOEA HYPOPNOEA INDEX (AHI): mild OSAS (AHI 5-15), moderate OSAS (AHI 15-30) and severe OSAS (AHI > 30). In the sample collected, 347 (262 males and 85 females) of 1185 patients suffered from mild OSAS, 363 (269 males and 94 females) from moderate OSAS and 475 (330 males and 145 females) from severe OSAS. In the group suffering from mild OSAS, we found: 127 patients affected by hypertension, 48 with diabetes, 11 with dyslipidaemia and 32 with metabolic syndrome. In the group with moderate OSAS there were 157 patients with hypertension, 63 with diabetes, 72 with dyslipidaemia and 47 with metabolic syndrome. In the group suffering from severe OSAS there were 244 patients with hypertension, 138 with diabetes, 47 with dyslipidaemia and 90 with metabolic syndrome. For data analysis, we used the Spearman correlation test adjusted according to Sidak between the dependent variable AHI and the independent variables BMI, ESS, average SO2 (SO(2med)), hypertension, diabetes mellitus, dyslipidaemia and metabolic syndrome. The results show different patterns of correlation in terms of statistical significance: BMI ρ(s) = 0.26, SO(2med) ρ(s) = -0:51, hypertension ρ(s) = -0.05, dyslipidaemia ρ(s) = 0.22 for women, and BMI ρ(s) = 0.53, ESS ρ(s) = 0.28, SO(2med) ρ(s) = -0.50, hypertension ρ(s) = 0.17, diabetes mellitus ρ(s) = 0.28 and metabolic syndrome ρ(s) = 0.26 for men. The results of the study confirm the existence of a statistically significant correlation between the severity of OSAS and BMI, ESS, average SO2, hypertension, diabetes mellitus, dyslipidaemia and metabolic syndrome.


Asunto(s)
Hipertensión/complicaciones , Síndrome Metabólico/complicaciones , Apnea Obstructiva del Sueño/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Adulto Joven
20.
Phys Chem Chem Phys ; 13(42): 18910-20, 2011 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-21814669

RESUMEN

Translationally cold caesium molecules are created by photoassociation below the 6s + 6p(1/2) excited state and selectively detected by resonance enhanced two photon ionization (RE2PI). A series of excited vibrational levels belonging to the 0(-)(g) symmetry is identified. The regular progression of the vibrational spacings and of the rotational constants of the 0(-)(g) (6s + 6p(1/2)) levels is strongly altered in two energy domains. These deviations are interpreted in terms of resonant coupling with deeply bound energy levels of two upper 0(-)(g) states dissociating into the 6s + 6p(3/2) and 6s + 5d(3/2) asymptotes. A theoretical model is proposed to explain the coupling and a quantum defect analysis of the perturbed level position is performed. Moreover, the resonant coupling changes dramatically the spontaneous decay products of the photoexcited molecules, strongly enhancing the decay into deeply bound levels of the a(3)Σ(+)(u) triplet state and of the X(1)Σ(+)(g) ground state. These results may be relevant when conceiving population transferring schemes in cold molecule systems.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...