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The detection of individual quanta of light is important for quantum communication, fluorescence lifetime imaging, remote sensing and more. Due to their high detection efficiency, exceptional signal-to-noise ratio and fast recovery times, superconducting-nanowire single-photon detectors (SNSPDs) have become a critical component in these applications. However, the operation of conventional SNSPDs requires costly cryocoolers. Here we report the fabrication of two types of high-temperature superconducting nanowires. We observe linear scaling of the photon count rate on the radiation power at the telecommunications wavelength of 1.5 µm and thereby reveal single-photon operation. SNSPDs made from thin flakes of Bi2Sr2CaCu2O8+δ exhibit a single-photon response up to 25 K, and for SNSPDs from La1.55Sr0.45CuO4/La2CuO4 bilayer films, this response is observed up to 8 K. While the underlying detection mechanism is not fully understood yet, our work expands the family of materials for SNSPD technology beyond the liquid helium temperature limit and suggests that even higher operation temperatures may be reached using other high-temperature superconductors.
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We developed superconducting nanowire single-photon detectors based on tungsten silicide, which show saturated internal detection efficiency up to a wavelength of 10 µm. These detectors are promising for applications in the mid-infrared requiring sub-nanosecond timing, ultra-high gain stability, low dark counts, and high efficiency, such as chemical sensing, LIDAR, dark matter searches, and exoplanet spectroscopy.
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As the limits of traditional von Neumann computing come into view, the brain's ability to communicate vast quantities of information using low-power spikes has become an increasing source of inspiration for alternative architectures. Key to the success of these largescale neural networks is a power-efficient spiking element that is scalable and easily interfaced with traditional control electronics. In this work, we present a spiking element fabricated from superconducting nanowires that has pulse energies on the order of â¼10 aJ. We demonstrate that the device reproduces essential characteristics of biological neurons, such as a refractory period and a firing threshold. Through simulations using experimentally measured device parameters, we show how nanowire-based networks may be used for inference in image recognition and that the probabilistic nature of nanowire switching may be exploited for modeling biological processes and for applications that rely on stochasticity.
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Nanocables , Redes Neurales de la Computación , NeuronasRESUMEN
Electromagnetic fields (EMFs) have been proposed as a tool to ameliorate bone formation and healing. Despite their promising results, however, they have failed to enter routine clinical protocols to treat bone conditions where higher bone mass has to be achieved. This is no doubt also due to a fundamental lack of knowledge and understanding on their effects and the optimal settings for attaining the desired therapeutic effects. This review analysed the available in vitro and in vivo studies that assessed the effects of sinusoidal EMFs (SEMFs) on bone and bone cells, comparing the results and investigating possible mechanisms of action by which SEMFs interact with tissues and cells. The effects of SEMFs on bone have not been as thoroughly investigated as pulsed EMFs; however, abundant evidence shows that SEMFs affect the proliferation and differentiation of osteoblastic cells, acting on multiple cellular mechanisms. SEMFs have also proven to increase bone mass in rodents under normal conditions and in osteoporotic animals.
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Huesos/citología , Campos Electromagnéticos , Osteoblastos/citología , Células 3T3 , Animales , Proteína Morfogenética Ósea 2/metabolismo , Diferenciación Celular , Proliferación Celular , Cilios/metabolismo , Humanos , Ratones , Osteoporosis , Células RAW 264.7 , Ratas , Especies Reactivas de Oxígeno/metabolismo , Transducción de SeñalRESUMEN
The basis for superconducting electronics can broadly be divided between two technologies: the Josephson junction and the superconducting nanowire. While the Josephson junction (JJ) remains the dominant technology due to its high speed and low power dissipation, recently proposed nanowire devices offer improvements such as gain, high fanout, and compatibility with CMOS circuits. Despite these benefits, nanowire-based electronics have largely been limited to binary operations, with devices switching between the superconducting state and a high-impedance resistive state dominated by uncontrolled hotspot dynamics. Unlike the JJ, they cannot increment an output through successive switching and their operation speeds are limited by their slow thermal-reset times. Thus, there is a need for an intermediate device with the interfacing capabilities of a nanowire but a faster, moderated response allowing for modulation of the output. We present a nanowire device based on controlled fluxon transport. We show that the device is capable of responding proportionally to the strength of its input, unlike other nanowire technologies. The device can be operated to produce a multilevel output with distinguishable states, the number of which can be tuned by circuit parameters. Agreement between experimental results and electrothermal circuit simulations demonstrates that the device is classical and may be readily engineered for applications including use as a multilevel memory.
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Renal angiomyolipoma (AML) is a benign mesenchymal tumour. AML often leads to haemorrhagic complications such as retroperitoneal haematoma. Treatment varies from case to case, ranging from minimally invasive approaches such as selective embolization of the renal artery to invasive wedge resection, partial nephrectomy or, in more severe cases, radical nephrectomy. Here we report a case of retroperitoneal haematoma secondary to AML, treated with conservative approach by super-selective embolization of the lower-pole segmental renal artery.
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Angiomiolipoma/terapia , Embolización Terapéutica , Neoplasias Renales/terapia , Nefrectomía , Adulto , Angiomiolipoma/cirugía , Femenino , Humanos , Neoplasias Renales/cirugíaRESUMEN
Hamartoma is a benign tumor-like malformation characterized by a focal mixture of mature cells and tissues normally present in affected area. The hamartoma of the breast is rare. We report a case in an asymptomatic young woman coming to our attention for a left breast lesion detected by ultrasound screening.
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Enfermedades de la Mama , Hamartoma , Adulto , Enfermedades de la Mama/diagnóstico , Femenino , Hamartoma/diagnóstico , HumanosRESUMEN
Neoadjuvant chemotherapy (NACT) in locally advanced breast tumors may allow an adequate control of the disease impossible with surgery alone. Moreover, NACT increases the chance of breast-conserving surgery. Between 2008 and 2012, we treated with NACT 83 patients with locally advanced breast cancer. We report the preliminary results evaluating the impact of NACT on the type of surgery.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/cirugía , Mastectomía Segmentaria , Terapia Neoadyuvante/métodos , Neoplasias de la Mama/patología , Quimioterapia Adyuvante/métodos , Femenino , Humanos , Estadificación de Neoplasias , Resultado del TratamientoRESUMEN
PURPOSE: This study was undertaken to compare the effectiveness of ultrasound-guided Hartmann's solution enema (US-E) and radiological liquid enema (RX-E) in reducing idiopathic ileocecocolic intussusceptions in relation to patient age and symptom duration. MATERIALS AND METHODS: The study group consisted of 42 patients with idiopathic ileocecocolic intussusception treated with US-E (20 patients) or RX-E (23 patients), with one patient undergoing both procedures owing to recurrence. Patients were divided into subgroups according to age (<6 months, 6-12 months, >12 months) and symptom duration (<12 h, 12-24 h, >24 h). RESULTS: Complete reduction was achieved in 15/20 patients treated with US-E (75%) and in 10/23 treated with RX-E (43.5%) (p=ns). Recurrence was observed in 1/20 US-E and 0/23 RX-E (p=ns) patients. No complications were encountered. US-E had a significantly higher success rate than RX-E in patients >12 months (p=0.0063) and with symptom duration >24 h (p=0.0361). No differences were found in the other subgroups (p=ns). CONCLUSIONS: US-E and RX-E are procedures of comparable value and safety in reducing idiopathic intussusception. US-E seems to be more effective in patients >12 months or with symptom duration >24 h. As US-E avoids radiation exposure, it should be considered the first-choice procedure for reducing idiopathic ileocecocolic intussusception, particularly in these two subgroups of patients.
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Enema/métodos , Enfermedades del Íleon/terapia , Intususcepción/terapia , Soluciones Isotónicas/uso terapéutico , Ultrasonografía Intervencional , Distribución de Chi-Cuadrado , Niño , Preescolar , Medios de Contraste/administración & dosificación , Diatrizoato de Meglumina/administración & dosificación , Enema/efectos adversos , Femenino , Humanos , Presión Hidrostática , Enfermedades del Íleon/diagnóstico por imagen , Lactante , Intususcepción/diagnóstico por imagen , Masculino , Radiografía Intervencional , Recurrencia , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
INTRODUCTION: Inflammatory myofibroblastic tumor (IMT) is a benign solid tumor of uncertain etiology. MATERIALS AND METHODS: We report a case of a 4-year-old Down syndrome affected child, who had a pancreatic mass identified by ultrasonography (US) and confirmed by computed tomography (CT). RESULTS: Monitoring of IMT was performed by serial US studies, and at follow-up after 4 years there was no relapse. DISCUSSION: As radical removal of the lesion was not possible, the patient was successfully treated with nonsteroidal anti-inflammatory drugs (NSAIDs). It was decided to monitor the lesion by serial US in order to reduce the number of CT examinations and thereby avoid excessive exposure to ionizing radiation. It is widely reported in the literature that repeated CT scans are associated with increased exposure to radiation which may cause cancer, a fact which should not be overlooked in children.
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BACKGROUND: A prospective phase II study was conducted to evaluate the efficacy and toxicity of the combination docetaxel (Taxotere) (DTX) and oxaliplatin (OXA) in ovarian cancer patients recurring after a platinum-free interval (PFI) >12 months. PATIENTS AND METHODS: DTX, 75 mg/m(2), was administered by 60 min i.v. infusion, followed by OXA, 100 mg/m(2), given by a 2 h i.v., on day 1 every 21 days. RESULTS: From October 2003 to June 2006, 43 ovarian cancer patients were enrolled. Median PFI was 26 months. All patients were available for response evaluation: 17 complete responses and 12 partial responses were registered, for an overall response rate of 67.4%. The median response duration was 10 months. Stable disease was documented in 11 patients (median duration = 5.5 months). The median time to progression and overall survival were 14 and 28 months. A total of 259 courses were administered. Grade 3-4 leukopenia was documented in 32.5% of the patients, while no case of severe anemia and thrombocytopenia was observed. Grade 3-4 neurotoxicity and grade 2 alopecia were observed in 9.3% and 34.9% of cases, respectively. CONCLUSION: DTX/OXA combination is an active regimen with a favorable toxicity profile, for treatment of recurrent platinum-sensitive ovarian cancer patients.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Neoplasias Ováricas/tratamiento farmacológico , Adulto , Anciano , Supervivencia sin Enfermedad , Docetaxel , Femenino , Humanos , Persona de Mediana Edad , Compuestos Organoplatinos/administración & dosificación , Compuestos Organoplatinos/efectos adversos , Neoplasias Ováricas/mortalidad , Oxaliplatino , Taxoides/administración & dosificación , Taxoides/efectos adversos , Resultado del TratamientoRESUMEN
A large proportion of patients hospitalised for severe neuromotor disorders are supported during the in-hospital rehabilitation program by family members. To target interventions of psychological support for these caregivers it can be of help to identify the causes of caregiver burden or specific needs. Anxiety and depression are common in caregivers and constitute, together with emotional distress caused by loneliness and reduced social activities, an important part of the caregiving burden. This paper presents results emerging from a clinical intervention of psychological support offered to caregivers of neuromotor patients, mainly post-stroke, who were undergoing a course of in-hospital rehabilitation. A psychometric assessment was carried out on a sample of 50 caregivers, spouses or children, at the beginning and end of the in-hospital rehabilitation period. The following questionnaires were used: the Revised Anxiety and Depression Scale (RADS), measuring anxiety and depression, the Caregiver Need Assessment (CNA), assessing needs related to the assisted patient, and the Family Strain Questionnaire (FSQ) for a broader assessment of the problems faced by caregivers. The Functional Independence Measure (FIM) was completed by the medical doctor. A significant reduction was found, between the beginning and end of the rehabilitation period, in the needs related to patient care on the CNA (p < 0.001). Caregiver females, in contrast to males, showed an improvement in mood compared to the beginning of the rehabilitation period (p < 0.05). About half of the sample had, at the beginning, a marked clinical level of anxiety while 22% of caregivers had a marked clinical level of depression. Caregivers who received intense psychological support, i.e. at least one interview with the psychologist per week, showed, in contrast to those who received 3-4 interviews during the entire rehabilitation period, a decline in thoughts of death (p < 0.05) and, in cases where baseline anxiety was above the clinical cut-off, a reduced level of anxiety (p < 0.05). At the beginning of rehabilitation, there emerged: higher anxiety scores in caregivers who live with their patient (p < 0.05) compared to those living alone or with others; an increase in depression scores in inverse proportion to the patient's age (p = 0.01); higher scores of emotional stress in spouses (p < 0.05) compared to children and in caregivers of patients with left hemisphere deficits (p < 0.05); a greater need for knowledge about the disease (p < 0.001) and more thoughts of death (p < 0.05) in caregivers of female patients. These characteristics may be considered "alarm signals" that should alert hospital medical staff to the need to seek psychological help for the caregiver. At the end of rehabilitation, a greater degree of psychological strain was observed in caregivers of patients with severe disability. High needs related to the assisted patient (p < 0.01), high scores of emotional stress (p < 0.05), problems of social involvement (p < 0.05) and thoughts of death about the patient (p < 0.05) were found in caregivers of patients who had persisting high motor disability or who were admitted for consequences of a left hemisphere lesion. High depression scores were also found in caregivers of patients with high residual cognitive disability (p < 0.05). This psychometric evaluation makes it possible to tailor the psychological support offered to the needs of each individual caregiver both during rehabilitation and in relation to eventual future developments. A multidisciplinary team approach to the caregiver can thus lead to a general reduction of caregiver strain.
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Cuidadores/psicología , Enfermedades Neuromusculares/rehabilitación , Adaptación Psicológica , Adulto , Anciano , Anciano de 80 o más Años , Ansiedad/etiología , Consejo/métodos , Depresión/etiología , Femenino , Humanos , Pacientes Internos , Comunicación Interdisciplinaria , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Psicometría , Psicoterapia/métodos , Aislamiento Social , Estrés Psicológico/etiología , Rehabilitación de Accidente Cerebrovascular , Encuestas y CuestionariosRESUMEN
Two studies were conducted that assessed health perceptions and functional health status among an urban, low-income population in the southeastern region of the United States. The first study was conducted with 176 hospitalized indigent patients prior to discharge from a county hospital. Patients were administered the Short Form-36 (SF-36) health status questionnaire and two additional questions regarding perceptions of health. The second study was conducted in the same geographic region with a nonhospitalized, low-income population. The SF-36 was administered by telephone to 546 randomly selected interview respondents. The results demonstrated consistent differences between black and white respondents in referents for self-perceived health. It is suggested that health expectations and perceptions may be indicative of the cultural, contextual, and social-political factors that affect the lives of this urban, low income population. The validity of global single-item health indicators for use among low-income populations is questioned. Further research is needed to develop patient-based measures that accurately reflect the meanings and values of low-income patient groups.
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Actitud Frente a la Salud , Negro o Afroamericano/estadística & datos numéricos , Indicadores de Salud , Población Blanca/estadística & datos numéricos , Adolescente , Adulto , Negro o Afroamericano/psicología , Anciano , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Pobreza , Reproducibilidad de los Resultados , Autoimagen , Sudeste de Estados Unidos , Población Urbana , Población Blanca/psicologíaRESUMEN
A giant aneurysm of the right callosomarginal artery is reported in a 3-month-old child. This location is rare: including our case reported here, only three cases have been described. Clinicoradiological findings are presented and the surgical procedure is illustrated.
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Aneurisma Intracraneal/diagnóstico , Femenino , Humanos , Lactante , Aneurisma Intracraneal/cirugía , Imagen por Resonancia Magnética , Examen Neurológico , Lóbulo Parietal , Tomografía Computarizada por Rayos XRESUMEN
The criteria by which the operative approaches to craniopharyngioma are chosen are still controversial. The authors performed a retrospective analysis in 32 patients with craniopharyngioma who were surgically treated. Results of neurological and psychological tests administered during the follow-up period were correlated with the surgical approach. On the basis of these preliminary data and a maximum follow-up period of 10 years, the authors conclude that the subfrontal approach to the craniopharyngioma and partial removal of its solid part appears to be associated with a lower morbidity rate and minor frontal lobe disorders.
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Daño Encefálico Crónico/etiología , Trastornos de la Conducta Infantil/etiología , Craneofaringioma/cirugía , Hipofisectomía/métodos , Examen Neurológico , Neoplasias Hipofisarias/cirugía , Complicaciones Posoperatorias/etiología , Adolescente , Niño , Preescolar , Terapia Combinada , Craneofaringioma/radioterapia , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Pruebas Neuropsicológicas , Irradiación Hipofisaria , Neoplasias Hipofisarias/radioterapia , Estudios RetrospectivosRESUMEN
In order to characterize neurological, intellectual and behavioral sequelae better after surgical treatment of brain abscess in childhood, 32 children were studied over a 10-year time span after treatment of a brain abscess. Depending on the clinical condition, surgical treatment consisted of simple aspiration through a burr hole or of total excision after craniotomy. There were only 3 postoperative deaths (9%). The scheduled time for long-term follow-up was 3 years after surgery. The patient assessment included information concerning the presence of seizures, accurate neurological examination, an EEG, and a battery of intellectual tests to evaluate the presence of behavioral-mental deficits. Late seizures developed in 7 of the 29 survivors. Five patients presented permanent hemiparesis after surgical treatment. It is noteworthy that the intellectual impairment observed was more severe in younger patients, while the behavioral disturbances were more marked in school-age children.
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Absceso Encefálico/cirugía , Trastornos de la Conducta Infantil/etiología , Enfermedades del Sistema Nervioso/etiología , Complicaciones Posoperatorias , Adolescente , Absceso Encefálico/patología , Niño , Preescolar , Electroencefalografía , Epilepsia/etiología , Epilepsia/fisiopatología , Femenino , Humanos , Lactante , Inteligencia , MasculinoAsunto(s)
Anomalías Múltiples , Agenesia del Cuerpo Calloso , Meningomielocele , Femenino , Humanos , Recién Nacido , MasculinoRESUMEN
Medulloblastoma constituted 28% of brain neoplasms among children referred to the Santobono Children's Hospital of Naples from 1973 through October 1984. The authors summarize their experience with 68 cases of medulloblastoma, which were managed with a multimodal institutional protocol involving surgery, chemotherapy and radiation therapy. The evolution of modern management is discussed, and particular attention is directed to the factors affecting the prognosis.