Deterministic preparation of superpositions of vacuum plus one photon by adaptive homodyne detection: experimental considerations

The preparation stage of optical qubits is an essential task in all the experimental setups employed for the test and demonstration of Quantum Optics principles. We consider a deterministic protocol for the preparation of qubits as a superposition of vacuum and one photon number states, which has the advantage to reduce the amount of resources required via phase-sensitive measurements using a local oscillator ('dyne detection'). We investigate the performances of the protocol using different phase measurement schemes: homodyne, heterodyne, and adaptive dyne detection (involving a feedback loop). First, we define a suitable figure of merit for the prepared state and we obtain an analytical expression for that in terms of the phase measurement considered. Further, we study limitations that the phase measurement can exhibit, such as delay or limited resources in the feedback strategy. Finally, we evaluate the figure of merit of the protocol for different mode-shapes handily available in an experimental setup. We show that even in the presence of such limitations simple feedback algorithms can perform surprisingly well, outperforming the protocols when simple homodyne or heterodyne schemes are employed.Comment: revised versio

A prospective study on contrast-enhanced magnetic resonance imaging of testicular lesions: distinctive features of Leydig cell tumours

OBJECTIVES: Up to 20 % of incidentally found testicular lesions are benign Leydig cell tumours (LCTs). This study evaluates the role of contrast-enhanced magnetic resonance imaging (MRI) in the identification of LCTs in a large prospective cohort study. MATERIALS AND METHODS: We enrolled 44 consecutive patients with at least one solid non-palpable testicular lesion who underwent scrotal MRI. Margins of the lesions, signal intensity and pattern of wash-in and wash-out were analysed by two radiologists. The frequency distribution of malignant and benign MRI features in the different groups was compared by using the chi-squared or Fisher's exact test. Sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy were calculated. RESULTS: The sensitivity of scrotal MRI to diagnose LCTs was 89.47 % with 95.65 % specificity; sensitivity for malignant lesions was 95.65 % with 80.95 % specificity. A markedly hypointense signal on T2-WI, rapid and marked wash-in followed by a prolonged washout were distinctive features significantly associated with LCTs. Malignant lesions were significantly associated with blurred margins, weak hypointense signal on T2-WI ,and weak and progressive wash-in. The overall diagnostic accuracy was 93 %. CONCLUSIONS: LCTs have distinctive contrast-enhanced MRI features that allow the differential diagnosis of incidental testicular lesions. KEY POINTS: • MRI is able to characterize testicular lesions suggesting a specific diagnosis. • Rapid and marked wash-in is a common feature of Leydig cell tumours. • Markedly hypointense T2-WI signal is significantly correlated with benign lesions. • Blurred margins and weak hypointense T2-WI signal are correlated with malignant tumours. • Weak and progressive wash-in features are present in 85 % of seminomatous lesions

Clinical presentation, management and follow-up of 83 patients with Leydig cell tumors of the testis: a prospective case-cohort study

LCTs are more frequent than generally believed, are associated with male infertility, cryptorchidism and gynecomastia, and should be treated conservatively (in compliant patients) with active surveillance, which appears to be a safe alternative to surgical enucleation. WHAT IS KNOWN ALREADY Increasing referrals for testicular imaging have led to an increase in findings of LCTs. The features and natural history of these tumors remain largely unknown, as the available studies are small and heterogeneous. LCTs were previously treated aggressively and follow-up data are lacking. STUDY DESIGN, SIZE, DURATION A case-cohort study of consecutive patients diagnosed with LCTs over a 10-year period was prospectively enrolled from 2009 to 2018 and compared to matched cohorts of patients with seminomas or no testicular lesions screened in the same timeframe. PARTICIPANTS/MATERIALS, SETTING, METHODS Of the 9949 inpatients and outpatients referred for scrotal ultrasound, a total of 83 men with LCTs were included. Enrolled subjects underwent medical history and clinical examination and were asked to undergo routine blood tests, hormone investigations (FSH, LH, total testosterone, estradiol, inhibin B, sex hormone-binding globulin (SHBG), prolactin), and semen analysis. Patients who consented also underwent contrast-enhanced ultrasound, elastography, gadolinium-enhanced scrotal magnetic resonance imaging, and hCG stimulation test (5000 IU i.m.) with serum total testosterone and estradiol measured at 0, 24, 48, and 72 hours. MAIN RESULTS AND THE ROLE OF CHANCE In total, 83 patients diagnosed with LCTs were compared against 90 patients diagnosed with seminoma and 2683 patients without testicular lesions (NoL). LCTs were diagnosed by enucleation (48.2%), orchiectomy (13.3%), or clinical surveillance (38.5%). Testicular volume, sperm concentration, and morphology were lower (P = 0.001, P = 0.001, and P < 0.001, respectively) in patients with LCTs than in the NoL group. FSH, LH, and SHBG were higher and the testosterone/LH ratio was lower in LCTs than in the NoL group (P < 0.001). The LCT group showed higher SHBG (P = 0.018), lower sperm concentration (P = 0.029), and lower motility (P = 0.049) than the seminoma group. Risk factors for LCTs were cryptorchidism (χ2 = 28.27, P < 0.001), gynecomastia (χ2 = 54.22, P < 0.001), and low testicular volume (χ2 = 11.13, P = 0.001). Five cases were recurrences or bilateral lesions; none developed metastases during follow-up (median, 66 months). LIMITATIONS, REASONS FOR CAUTION This study has some limitations. First, hCG and second-line diagnostic investigations were not available for all tumor patients. Second, ours is a referral center for infertility, thus a selection bias may have altered the baseline features of the LCT population. However, given that the comparison cohorts were also from the same center and had been managed with a similar protocol, we do not expect a significant effect. WIDER IMPLICATIONS OF THE FINDINGS LCTs are strongly associated with male infertility, cryptorchidism, and gynecomastia, supporting the hypothesis that testicular dysgenesis syndrome plays a role in their development. Patients with LCTs are at a greater risk of endocrine and spermatogenesis abnormalities even when the tumor is resected, and thus require long-term follow-up and prompt efforts to preserve fertility after diagnosis. LCTs have a good oncological prognosis when recognized early, as tissue-sparing enucleation is curative and should replace orchiectomy. Conservative surgery and, in compliant patients, active surveillance through clinical and radiological follow-up are safe options, but require monitoring of testicular failure and recurrence

Cobalt oxide nanomaterials prepared by CVD as negative electrodes in lithium batteries

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Rhizobacterium and acibenzolar-S-methyl (ASM) in resistance induction against bacterial blight and expression of defense responses in cotton.

O efeito do acibenzolar-S-metil (ASM) e do isolado rizobacteriano L2-1 (bacillus cereus), aplicados isoladamente ou simultaneamente, foi avaliado em plantas de algodão na indução de resistência contra Xanthomonas axonopodis pv. malvarearum. Não houve efeito sinergístico quando se utilizou o ASM simultaneamente com o isolado L2-1. Quando o ASM e a rizobactéria foram aplicados simultaneamente, a atividade das enzimas foi sempre inferior ao tratamento em que o ASM foi aplicado isoladamente

Resistência a antimicrobianos em Campylobacter jejuni isolados de frangos de corte entre 2010 e 2011.

Projeto/Plano de Ação: 03.08.06.004

Estudo longitudinal da colonização de frangos de corte por campylobacter termófilos.

Projeto/Plano de Ação: 03.08.06.004

Vision Impairment and Blindness in New Brunswick Nursing Homes

A vision assessment program carried out in all nursing homes examined 89.3 percent of all residents. Results provide documentation of vision loss and blindness in the sample. The data show increasing levels of vision loss and blindness with age. This study documents the contribution of such impairment to increasing levels of supervision and nursing care. It is also evident that increasing vision loss reduces mobility, thus limiting the range of physical and intellectual activities of aged persons. The major contributory factors to vision impairment are ocular and systemic diseases. The prevalence of these conditions is established. A need is demon­strated for provision of vision care in nursing homes. The study suggests that the application of available technology for vision assessment and remediation could restore or improve the visual capability of a substantial number of persons suffering from vision impairment or blindness. The presence of age related increases in intraocular pressure and previously undetected glaucoma offers preventive opportunity