On the Recovery and Resolution of Exponential Relaxation Rates from Experimental Data: A Singular-Value Analysis of the Laplace Transform Inversion in the Presence of Noise

The problem of numerical inversion of the Laplace transform is considered when the inverse function is of bounded, strictly positive support. The recent eigenvalue analysis of McWhirter and Pike for infinite support has been generalized by numerical calculations of singular values. A priori knowledge of the support is shown to lead to increased resolution in the inversion, and the number of exponentials that can be recovered in given levels of noise is calculated

A method for space-variant deblurring with application to adaptive optics imaging in astronomy

Images from adaptive optics systems are generally affected by significant distortions of the point spread function (PSF) across the field of view, depending on the position of natural and artificial guide stars. Image reduction techniques circumventing or mitigating these effects are important tools to take full advantage of the scientific information encoded in AO images. The aim of this paper is to propose a method for the deblurring of the astronomical image, given a set of samples of the space-variant PSF. The method is based on a partitioning of the image domain into regions of isoplanatism and on applying suitable deconvolution methods with boundary effects correction to each region. The effectiveness of the boundary effects correction is proved. Moreover, the criterion for extending the disjoint sections to partially overlapping sections is validated. The method is applied to simulated images of a stellar system characterized by a spatially variable PSF. We obtain good photometric quality, and therefore good science quality, by performing aperture photometry on the deblurred images. The proposed method is implemented in IDL in the Software Package "Patch", which is available on http://www.airyproject.eu.Comment: 11 pages, 9 figures, 7 tables, accepted by A&

Low-Grade Uterine Endometrial Stromal Sarcoma: Prognostic Analysis of Clinico-Pathological Characteristics, Surgical Management, and Adjuvant Treatments. Experience From Two Referral Centers

OBJECTIVE: Low-grade uterine endometrial stromal sarcoma (LG-ESS) is a rare tumor characterized by an overall good survival but showing a indolent behavior and a variable risk of recurrence. There is no clear consensus on the optimal management of these tumors and no prognostic or predictive factors have been established. With this study, we evaluated the prognostic relevance of several clinical, surgical, and pathological features in patients affected by LG-ESS to identify risk factors associated with recurrence. METHODS: We retrospectively analyzed 52 LG-ESS cases, treated from January 1st, 1994, to May 31st, 2020, in two referral centers. The relationship between recurrence and clinicopathological characteristics as well as surgical treatment was investigated. Risk of recurrence and disease-free survival (DFS) were estimated by Cox regression and the Kaplan-Meier analysis, respectively. RESULTS: Of 52 patients with LG-ESS, 8 experienced recurrence (15%). The median follow-up was 100 months (SD ± 96, range: 15–336). By univariate analysis, fragmentation/morcellation, tumor size, FIGO stage, higher mitotic count, presence of necrosis, and lymphovascular space invasion (LSVI) resulted associated with a poorer outcome. Conversely, the surgical modality (laparotomic vs laparoscopic and hysterectomy with bilateral salpingo-oophorectomy vs local excision) and pelvic lymphadenectomy were not. Even the different modalities of adjuvant therapy (hormonal therapy, radiotherapy, and chemotherapy) showed no prognostic significance. Tumor fragmentation/morcellation and higher mitotic count resulted independent prognostic variables at multivariate analysis. CONCLUSIONS: This data supports the avoidance of any type of morcellation if LG-ESS is suspected preoperatively. Higher mitotic count and, possibly, tumor size, advanced FIGO stage, necrosis, and LVSI could be exploited to tailor the adjuvant therapy, but these results need to be confirmed in larger prospective studies

Brain Metastases from Ovarian Cancer: Current Evidence in Diagnosis, Treatment, and Prognosis

With this review, we provide the state of the art concerning brain metastases (BMs) from ovarian cancer (OC), a rare condition. Clinical, pathological, and molecular features, treatment options, and future perspectives are comprehensively discussed. Overall, a diagnosis of high-grade serous OC and an advanced disease stage are common features among patients who develop brain metastases. BRCA1 and BRCA2 gene mutations, as well as the expression of androgen receptors in the primary tumor, are emerging risk and prognostic factors which could allow one to identify categories of patients at greater risk of BMs, who could benefit from a tailored follow-up. Based on present data, a multidisciplinary approach combining surgery, radiotherapy, and chemotherapy seem to be the best approach for patients with good performance status, although the median overall survival (<1 year) remains largely disappointing. Hopefully, novel therapeutic avenues are being explored, like PARP inhibitors and immunotherapy, based on our improved knowledge regarding tumor biology, but further investigation is warranted

Experimental photonic generation of chirped pulses using nonlinear dispersion-based incoherent processing

“© 2015 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited"We experimentally demonstrate, for the first time, a chirped microwave pulses generator based on the processing of an incoherent optical signal by means of a nonlinear dispersive element. Different capabilities have been demonstrated such as the control of the time-bandwidth product and the frequency tuning increasing the flexibility of the generated waveform compared to coherent techniques. Moreover, the use of differential detection improves considerably the limitation over the signal-to-noise ratio related to incoherent processing.The research leading to these results has received funding from the national project TEC2011-26642 ( NEWTON) funded by the Ministerio de Ciencia y Tecnologia and the regional project GVA PROMETEOII2013/012.Rius Mercado, M.; Bolea Boluda, M.; Mora Almerich, J.; Ortega Tamarit, B.; Capmany Francoy, J. (2015). Experimental photonic generation of chirped pulses using nonlinear dispersion-based incoherent processing. Optics Express. 23(10):13634-13640. https://doi.org/10.1364/OE.23.013634S13634136402310Yao, J. (2010). Arbitrary waveform generation. Nature Photonics, 4(2), 79-80. doi:10.1038/nphoton.2009.276Li, M., Azaña, J., Zhu, N., & Yao, J. (2014). Recent progresses on optical arbitrary waveform generation. Frontiers of Optoelectronics, 7(3), 359-375. doi:10.1007/s12200-014-0470-yCapmany, J., & Novak, D. (2007). Microwave photonics combines two worlds. Nature Photonics, 1(6), 319-330. doi:10.1038/nphoton.2007.89Wang, J., Shen, H., Fan, L., Wu, R., Niu, B., Varghese, L. T., … Qi, M. (2015). Reconfigurable radio-frequency arbitrary waveforms synthesized in a silicon photonic chip. Nature Communications, 6(1). doi:10.1038/ncomms6957Maleki, L. (2011). The optoelectronic oscillator. Nature Photonics, 5(12), 728-730. doi:10.1038/nphoton.2011.293Matsko, A. B., Maleki, L., Savchenkov, A. A., & Ilchenko, V. S. (2003). Whispering gallery mode based optoelectronic microwave oscillator. Journal of Modern Optics, 50(15-17), 2523-2542. doi:10.1080/09500340308233582Bolea, M., Mora, J., Ortega, B., & Capmany, J. (2010). Photonic arbitrary waveform generation applicable to multiband UWB communications. Optics Express, 18(25), 26259. doi:10.1364/oe.18.026259Zhang, M.-J., Liu, T.-G., Wang, A.-B., Zheng, J.-Y., Meng, L.-N., Zhang, Z.-X., & Wang, Y.-C. (2011). Photonic ultrawideband signal generator using an optically injected chaotic semiconductor laser. Optics Letters, 36(6), 1008. doi:10.1364/ol.36.001008Bertero, M., Miyakawa, M., Boccacci, P., Conte, F., Orikasa, K., & Furutani, M. (2000). Image restoration in chirp-pulse microwave CT (CP-MCT). IEEE Transactions on Biomedical Engineering, 47(5), 690-699. doi:10.1109/10.841341Li, M., Wang, C., Li, W., & Yao, J. (2010). An Unbalanced Temporal Pulse-Shaping System for Chirped Microwave Waveform Generation. IEEE Transactions on Microwave Theory and Techniques, 58(11), 2968-2975. doi:10.1109/tmtt.2010.2079070Hao Chi, & Jianping Yao. (2008). Chirped RF Pulse Generation Based on Optical Spectral Shaping and Wavelength-to-Time Mapping Using a Nonlinearly Chirped Fiber Bragg Grating. Journal of Lightwave Technology, 26(10), 1282-1287. doi:10.1109/jlt.2008.917768Wang, C., & Yao, J. (2008). Photonic Generation of Chirped Millimeter-Wave Pulses Based on Nonlinear Frequency-to-Time Mapping in a Nonlinearly Chirped Fiber Bragg Grating. IEEE Transactions on Microwave Theory and Techniques, 56(2), 542-553. doi:10.1109/tmtt.2007.914639Chi, H., & Yao, J. (2007). All-Fiber Chirped Microwave Pulses Generation Based on Spectral Shaping and Wavelength-to-Time Conversion. IEEE Transactions on Microwave Theory and Techniques, 55(9), 1958-1963. doi:10.1109/tmtt.2007.904084Chao Wang, & Jianping Yao. (2010). Large Time-Bandwidth Product Microwave Arbitrary Waveform Generation Using a Spatially Discrete Chirped Fiber Bragg Grating. Journal of Lightwave Technology, 28(11), 1652-1660. doi:10.1109/jlt.2010.2047093Chao Wang, & Jianping Yao. (2009). Chirped Microwave Pulse Generation Based on Optical Spectral Shaping and Wavelength-to-Time Mapping Using a Sagnac Loop Mirror Incorporating a Chirped Fiber Bragg Grating. Journal of Lightwave Technology, 27(16), 3336-3341. doi:10.1109/jlt.2008.2010561Li, M., & Yao, J. (2011). Photonic Generation of Continuously Tunable Chirped Microwave Waveforms Based on a Temporal Interferometer Incorporating an Optically Pumped Linearly Chirped Fiber Bragg Grating. IEEE Transactions on Microwave Theory and Techniques, 59(12), 3531-3537. doi:10.1109/tmtt.2011.2169078Bolea, M., Mora, J., Ortega, B., & Capmany, J. (2012). Nonlinear dispersion-based incoherent photonic processing for microwave pulse generation with full reconfigurability. Optics Express, 20(6), 6728. doi:10.1364/oe.20.006728Dorrer, C. (2009). Statistical analysis of incoherent pulse shaping. Optics Express, 17(5), 3341. doi:10.1364/oe.17.003341Park, Y., & Azaña, J. (2010). Ultrahigh dispersion of broadband microwave signals by incoherent photonic processing. Optics Express, 18(14), 14752. doi:10.1364/oe.18.01475

Nonlinear dispersion-based incoherent photonic processing for microwave pulse generation with full reconfigurability

This paper was published in OPTICS EXPRESS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-20-6-6728. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under lawA novel all-optical technique based on the incoherent processing of optical signals using high-order dispersive elements is analyzed for microwave arbitrary pulse generation. We show an approach which allows a full reconfigurability of a pulse in terms of chirp, envelope and central frequency by the proper control of the second-order dispersion and the incoherent optical source power distribution, achieving large values of timebandwidth product.The research leading to these results has received funding from the national project TEC TEC2011-26642 (NEWTON) funded by the Ministerio de Ciencia y Tecnologia, the regional project PROMETEO GVA 2008/092 MICROWAVE PHOTONICS and the complementary grant for I + D projects for quality groups by Generalitat Valenciana ACOMP/2010/196.Bolea Boluda, M.; Mora Almerich, J.; Ortega Tamarit, B.; Capmany Francoy, J. (2012). Nonlinear dispersion-based incoherent photonic processing for microwave pulse generation with full reconfigurability. Optics Express. 20:6728-6736. doi:10.1364/OE.20.006728S672867362