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The influence of the Mott physics on the doping-temperature phase diagram of copper oxides represents a major issue that is subject of intense theoretical and experimental effort. Here, we investigate the ultrafast electron dynamics in prototypical single-layer Bi-based cuprates at the energy scale of the O-2pâCu-3d charge-transfer (CT) process. We demonstrate a clear evolution of the CT excitations from incoherent and localized, as in a Mott insulator, to coherent and delocalized, as in a conventional metal. This reorganization of the high-energy degrees of freedom occurs at the critical doping pcr ≈0.16 irrespective of the temperature, and it can be well described by dynamical mean field theory calculations. We argue that the onset of the low-temperature charge instabilities is the low-energy manifestation of the underlying Mottness that characterizes the p < pcr region of the phase diagram. This discovery sets a new framework for theories of charge order and low-temperature phases in underdoped copper oxides.
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Multimode entanglement is an essential resource for quantum information processing and quantum metrology. However, multimode entangled states are generally constructed by targeting a specific graph configuration. This yields to a fixed experimental setup that therefore exhibits reduced versatility and scalability. Here we demonstrate an optical on-demand, reconfigurable multimode entangled state, using an intrinsically multimode quantum resource and a homodyne detection apparatus. Without altering either the initial squeezing source or experimental architecture, we realize the construction of thirteen cluster states of various sizes and connectivities as well as the implementation of a secret sharing protocol. In particular, this system enables the interrogation of quantum correlations and fluctuations for any multimode Gaussian state. This initiates an avenue for implementing on-demand quantum information processing by only adapting the measurement process and not the experimental layout.
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Instantaneous quantum computing is a subuniversal quantum complexity class, whose circuits have proven to be hard to simulate classically in the discrete-variable realm. We extend this proof to the continuous-variable (CV) domain by using squeezed states and homodyne detection, and by exploring the properties of postselected circuits. In order to treat postselection in CVs, we consider finitely resolved homodyne detectors, corresponding to a realistic scheme based on discrete probability distributions of the measurement outcomes. The unavoidable errors stemming from the use of finitely squeezed states are suppressed through a qubit-into-oscillator Gottesman-Kitaev-Preskill encoding of quantum information, which was previously shown to enable fault-tolerant CV quantum computation. Finally, we show that, in order to render postselected computational classes in CVs meaningful, a logarithmic scaling of the squeezing parameter with the circuit size is necessary, translating into a polynomial scaling of the input energy.
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Many-body interactions with the underlying bulk electrons determine the properties of confined electronic states at the surface of a metal. Using momentum resolved nonlinear photoelectron spectroscopy we show that one can tailor these many-body interactions in graphite, leading to a strong renormalization of the dispersion and linewidth of the image potential state. These observations are interpreted in terms of a basic self-energy model, and may be considered as exemplary for optically induced many-body interactions.
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STUDY OBJECTIVE: To analyze bowel and urinary function in patients with posterior deep infiltrating endometriosis (DIE) >30 mm in largest diameter at transvaginal ultrasound before and after surgical nerve-sparing excision. DESIGN: Prospective observational study (Canadian Task Force classification III). SETTING: Tertiary care university hospital in Bologna, Italy. PATIENTS: Twenty-five patients with posterior DIE were included in the study between June 2011 and December 2012. Patients did not receive hormone therapy for at least 3 months before and 6 months after surgery. INTERVENTIONS: Patients underwent urodynamic studies and anorectal manometry before and after nerve-sparing laparoscopic excision of the posterior DIE nodule. MEASUREMENTS AND MAIN RESULTS: Intestinal and urinary function was evaluated in patients with bulky posterior DIE using urodynamic and anorectal manometry. Results of urodynamic studies and anorectal manometry were similar before and after nerve-sparing surgical excision of the posterior DIE nodule. Urodynamic studies demonstrated a high prevalence of voiding dysfunction, whereas anorectal manometry showed no reduction in rectoanal inhibitory reflex and hypertone of the internal anal sphincter. CONCLUSIONS: Patients with posterior DIE >30 mm in greatest diameter demonstrate preoperative dysfunction at urodynamic study and anorectal manometry, probably due to DIE per se. The nerve-sparing surgical approach seems not to influence the motility or sensory capacity of the bladder and the rectosigmoid colon.
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Endometriosis/cirugía , Laparoscopía , Urodinámica , Adulto , Canal Anal/inervación , Canal Anal/fisiopatología , Endometriosis/fisiopatología , Femenino , Humanos , Italia , Laparoscopía/efectos adversos , Laparoscopía/métodos , Laparoscopía/rehabilitación , Manometría , Proyectos Piloto , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/fisiopatología , Periodo Posoperatorio , Periodo Preoperatorio , Estudios Prospectivos , Recto/inervación , Recto/fisiopatologíaRESUMEN
A major challenge in understanding the cuprate superconductors is to clarify the nature of the fundamental electronic correlations that lead to the pseudogap phenomenon. Here we use ultrashort light pulses to prepare a non-thermal distribution of excitations and capture novel properties that are hidden at equilibrium. Using a broadband (0.5-2 eV) probe, we are able to track the dynamics of the dielectric function and unveil an anomalous decrease in the scattering rate of the charge carriers in a pseudogap-like region of the temperature (T) and hole-doping (p) phase diagram. In this region, delimited by a well-defined T*neq(p) line, the photoexcitation process triggers the evolution of antinodal excitations from gapped (localized) to delocalized quasiparticles characterized by a longer lifetime. The novel concept of photo-enhanced antinodal conductivity is naturally explained within the single-band Hubbard model, in which the short-range Coulomb repulsion leads to a k-space differentiation between nodal quasiparticles and antinodal excitations.
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The effect of different thermal processing conditions just after fermentation on physicochemical parameters and sensory attributes of salami and chorizo slices dried by Quick-Dry-Slice process®, was evaluated. Meat and common additives were mixed, stuffed and fermented. Previous to drying the sausages were subjected to thermal treatment at 53 °C at different exposure times (0, 50, 65, 80, 95 and 110 min). Finally, the sausages were sliced and dried using QDS process®. Color, instrumental texture and sensory analysis were performed. Lightness (L*) after fermentation increased with thermal processing in both products while redness (a*) and yellowness (b*) decreased only in salami. Thermal treatment after fermentation increased the initial force (F0). Cooked appearance, cooked fat odor, cooked flavor and stringiness increased when the thermal processing time was increased. Thermal processing of salami and chorizo at 53 °C for 50 min and drying up to 30% of weight loss resulted in a similar product to that obtained without thermal processing.
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Fenómenos Químicos , Fermentación , Manipulación de Alimentos/métodos , Productos de la Carne/análisis , Color , Culinaria , Desecación , Calor , Humanos , Concentración de Iones de Hidrógeno , Odorantes , GustoRESUMEN
Ultrafast broadband transient reflectivity experiments are performed to study the interplay between the nonequilibrium dynamics of the pseudogap and the superconducting phases in Bi(2)Sr(2}Ca(0.92)Y(0.08)Cu(2)O(8+δ). Once superconductivity is established, the relaxation of the pseudogap proceeds ~2 times faster than in the normal state, and the corresponding transient reflectivity variation changes sign after ~0.5 ps. The results can be described by a set of coupled differential equations for the pseudogap and for the superconducting order parameter. The sign and strength of the coupling term suggest a remarkably weak competition between the two phases, allowing their coexistence.
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BACKGROUND: Laparoscopic segmental resection as a treatment for intestinal endometriosis can be supported by favorable clinical outcomes, but carries a high risk of major complications. The purpose of this study is to evaluate histopathological patterns of colorectal endometriosis and investigate potential relationships between histological findings and clinical data. METHODS: We consecutively included 47 patients treated with laparoscopic segmental resection because of symptomatic colorectal endometriosis. All patients underwent follow-up for a median of 18 months (range: 6-35). We examined the histological patterns of colorectal endometriosis and evaluated the relationships between histological findings (satellite lesions, positive margins and vertical infiltration) and clinical outcomes (incidence of recurrence, quality of life and symptom improvement). Moreover, we observed if satellite lesions could influence preoperative scores of the short form-36 health survey (SF-36) questionnaire and visual analogue score (VAS) for pain symptoms. RESULTS: There were no statistically significant differences in terms of anatomical and pain recurrences, pain symptoms and quality of life improvement among patients with or without positive margins, satellite lesions and different degrees of vertical infiltration (P > 0.05). Furthermore, women with or without satellite lesions were no different in terms of preoperative VAS of pain symptoms and SF-36 scores (P > 0.05). CONCLUSIONS: The presence of satellite lesions or positive resection margins does not seem to influence clinical outcomes of segmental colorectal resection. Similarly, satellite lesions do not appear to have a major role in determining preoperative clinical presentation. These results may be useful to reconsider the surgical strategy for bowel endometriosis.
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Enfermedades del Colon/cirugía , Endometriosis/cirugía , Tracto Gastrointestinal/cirugía , Enfermedades del Recto/cirugía , Enfermedades del Colon/patología , Endometriosis/patología , Femenino , Estudios de Seguimiento , Humanos , Complicaciones Posoperatorias , Calidad de Vida , Enfermedades del Recto/patología , Recurrencia , Resultado del TratamientoRESUMEN
Unveiling the nature of the bosonic excitations that mediate the formation of Cooper pairs is a key issue for understanding unconventional superconductivity. A fundamental step toward this goal would be to identify the relative weight of the electronic and phononic contributions to the overall frequency (Ω)-dependent bosonic function, Π(Ω). We performed optical spectroscopy on Bi(2)Sr(2)Ca(0.92)Y(0.08)Cu(2)O(8+δ) crystals with simultaneous time and frequency resolution; this technique allowed us to disentangle the electronic and phononic contributions by their different temporal evolution. The spectral distribution of the electronic excitations and the strength of their interaction with fermionic quasiparticles fully account for the high critical temperature of the superconducting phase transition.
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As is well-known, the character of the π orbitals is of paramount importance for the chemical properties of the carbon allotropes and their derived compounds. While at equilibrium the nature of these orbitals is well understood, their photoinduced nonequilibrium behavior is under investigation. Here, we demonstrate that when a UV-laser pulse excites a carrier density larger than 10% of the π* density of state in graphite, a renormalization of the π-π* band gap takes place. This result has been achieved by detecting the transient reflectivity and the associated decay time of an infrared probe following the excitation of a UV pump pulse tuned across the π-π* absorption resonance. The pump photon energy at which both the transient reflectivity and the decay time are maximum is downshifted by 500 meV with respect to the relative absorption maximum at equilibrium. This finding is interpreted as a transient π-π* band gap shrinking of similar magnitude, near the M point of the Brillouin zone.
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In this work we report on the measurement of the Young modulus of the external surface of Clostridium tyrobutyricum spores in air with an atomic force microscope. The Young modulus can be reliably measured despite the strong tip-spore adhesion forces and the need to immobilize the spores due to their slipping on most substrates. Moreover, we investigate the disturbing factors and consider some practical aspects that influence the measurements of elastic properties of biological objects with the atomic force microscopy indentation techniques.
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Clostridium tyrobutyricum/fisiología , Clostridium tyrobutyricum/ultraestructura , Esporas/fisiología , Esporas/ultraestructura , Elasticidad , Microscopía de Fuerza Atómica/métodos , Estrés MecánicoRESUMEN
The aim of this study was to determine the effect of different dietary fatty acid profiles on the main fat depots of broiler chickens: skin including s.c. fat (SK) and abdominal fat pad (AF). One hundred forty-four female broiler chickens were fed a low-fat diet (B; 0.5% of added fat) or diets supplemented with 10% of tallow (T), sunflower oil rich in oleic acid (SOO), sunflower oil rich in linoleic acid (SOL), linseed oil rich in linolenic acid (LO), or a mix of fats (M: 55% of T + 35% of LO + 10% SOL) that contained one-third each of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids. The animals were housed in 36 cages and were randomly distributed into 6 dietary treatments with 6 replicates each. Experimental diets were evaluated for apparent total fatty acid availability and AME. On d 42, birds were slaughtered to determine the weight of AF and SK and fatty acid profile. Regarding the diets containing 10% added fat, the highest saturated diet (T) resulted in the lowest values of apparent total fatty acid availability and percentage of AME. Animals fed the most polyunsaturated diet (LO) had a lower SK deposition than those fed the saturated diet, on both an absolute (LO: 145 vs. T: 159 and M: 168 g; P < 0.001) and a relative basis (LO: 6.94 vs. T: 7.39 and M: 7.52 g/100 g of BW; P < 0.001). Furthermore, the lowest AF depot was observed in the LO diet (LO: 26.3 g vs. T: 37.6 and M: 39.9 g; P < 0.001). The added fat treatments caused significant but similar changes in fatty acid profile of both studied tissues. In conclusion, feeding broiler chickens polyunsaturated fatty acids, in comparison to dietary saturated fatty acids, reduced the amount of both AF and SK by approximately 30 and 9%, respectively.
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Grasa Abdominal/metabolismo , Pollos/metabolismo , Grasas Insaturadas en la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Grasa Subcutánea/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Disponibilidad Biológica , Pollos/crecimiento & desarrollo , Grasas de la Dieta/metabolismo , Grasas Insaturadas en la Dieta/metabolismo , Relación Dosis-Respuesta a Droga , Grasas , Femenino , Ácido Linoleico , Ácido Oléico , Aceites de Plantas , Aceite de Girasol , Aumento de PesoAsunto(s)
Antibacterianos , Quimioterapia Combinada/uso terapéutico , Gastritis/tratamiento farmacológico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/efectos de los fármacos , Linfoma de Células B de la Zona Marginal/tratamiento farmacológico , Neoplasias Gástricas/tratamiento farmacológico , Úlcera Gástrica/tratamiento farmacológico , Ensayos Clínicos como Asunto , Farmacorresistencia Microbiana , Humanos , Resultado del TratamientoRESUMEN
OBJECTIVE: This study analyzes the effect of short- and long-term omeprazole (OM) on duodenal ulcer healing, recurrence, and H. pylori status. METHODS: Patients affected by active duodenal ulcer were randomly allocated to treatment with OM 20 mg or 40 mg once daily for 4 wk. Subsequently, patients with healed duodenal ulcer were randomly assigned to one of the following three groups: OM 20 mg once daily for 12 months, OM 20 mg alternate days for 12 months, and no treatment. Endoscopy was performed at entry, at 4 wk, and after 4, 8, and 12 months. Two biopsy specimens from antrum, body, and fundus were taken for histology and search for H. pylori. One hundred and eighty patients with active duodenal ulcer were admitted. Ninety-one were treated with OM 20 mg once daily and 89 with OM 40 mg for 4 wk. RESULTS: The results at 4 wk show 92.8% patients healed with OM 20 mg and 95.1% at 40 mg (NS). In the second part of the study, 96 of the patients who healed at 4 wk (45 with OM 20 mg, and 51 with OM 40 mg) entered the long-term study. Thirty-six patients received OM 20 mg daily for 12 months, 35 OM 20 mg on alternate days for 12 months, and 25 patients no treatment. The results show a healing rate of 100%, 100%, and 95% with OM 20 mg daily, of 97%, 95%, and 93% with OM 20 mg on alternate days, and of 81%, 50%, and 40% (p < 0.01) with no treatment at 4, 8, and 12 months, respectively. H. pylori that was found in 97% of patients at entry, at 4 wk was found in 92.8% of patients treated with OM 20 mg and in 97.5% of patients treated with OM 40 mg (NS). In one-third of the patients, H. pylori disappeared from the antrum but was found in the fundus. A 30% reduction in the presence of H. pylori was seen in the group treated with 20 mg daily for 12 months. CONCLUSIONS: We conclude that both continuous and alternate-day long-term OM treatment at 20 mg are similarly efficacious in the prevention of duodenal ulcer recurrence. Healing active duodenal ulcers with 20 or 40 mg does not influence subsequent treatment. Long-term OM at 20 mg daily for 12 months suppresses H. pylori temporarily in one-third of the patients. In these patients however, H. pylori reactivates after the end of treatment.
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Úlcera Duodenal/tratamiento farmacológico , Úlcera Duodenal/prevención & control , Helicobacter pylori/efectos de los fármacos , Omeprazol/administración & dosificación , Adulto , Esquema de Medicación , Úlcera Duodenal/microbiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Omeprazol/efectos adversos , Omeprazol/uso terapéutico , Estómago/microbiología , Resultado del TratamientoRESUMEN
The experience with pneumatic dilatation of the cardia under endoscopic control in 10 patients with achalasia is reported. For dilatation a modified Witzel dilator on a fiberscope was used; progressive pressures from 100 to 300 mmHg were applied; the dilatations were repeated at increasing intervals of time for a period of 1 year. The clinical, radiological, endoscopic and manometric results were satisfactory. Dynamic scintigraphy was performed in 3 patients before treatment, and after the fourth dilatation. No important complications were observed.