Seven-day antibiotic therapy for Enterobacterales bacteremia in high-risk neutropenic patients: toward a new paradigm.

Purpose: Data on short courses of antibiotic therapy for Enterobacterales bacteremia in high-risk neutropenic patients are limited. The aim of the study was to describe and compare the frequency of bacteremia relapse, 30-day overall and infection-related mortality, Clostridiodes difficile infection and length of hospital stay since bacteremia among those who received antibiotic therapy for 7 or 14 days.

Methods: This is a multicenter, prospective, observational cohort study in adult high-risk neutropenic patients with hematologic malignancies or hematopoietic stem cell transplant and monomicrobial Enterobacterales bacteremia.

Ceftazidime-Avibactam Improves Outcomes in High-Risk Neutropenic Patients with Carbapenemase-Producing Enterobacterales Bacteremia.

Few studies have evaluated the efficacy of ceftazidime-avibactam (CA) for carbapenemase-producing Enterobacterales bacteremia (KPC-PEB) in high-risk neutropenic patients. This is a prospective multicenter observational study in high-risk neutropenic patients with multi-drug resistant Enterobacterales bacteremia. They were compared according to the resistance mechanism and definitive treatment provided: KPC-CPE treated with CA (G1), KPC-CPE treated with other antibiotics (G2), and patients with ESBL-producing Enterobacterales bacteremia who received appropriate definitive therapy (G3).

Particle swarm optimization-assisted approach for the extraction of VCSEL model parameters.

We propose a direct particle swarm optimization (PSO) method for extracting the parameters of a physical model describing the behavior of vertical-cavity surface-emitting lasers (VCSELs), starting from the light-current (L-I) characteristics and the small signal modulation (S21) responses, at different currents and temperatures. With an optimal choice of hyperparameters of the algorithm, the method is able to predict parameters that accurately reproduce the behavior of the device. Its prediction capabilities are compared to those of two commonly used nonlinear optimizers (Interior Point and Levenberg-Marquardt), to benchmark its performances.

Design and performance assessment of modular multi-band photonic-integrated WSS.

Today, optical transport and data center networks extensively utilize photonic integrated systems due to their large bandwidth and a high degree of reconfigurability. In addition to these properties, photonic integrated-based systems can deliver an overall low fabrication cost, a small footprint, and low power consumption. In this perspective, we present a modular photonic integrated multi-band wavelength selective switch (WSS) capable of managing a wide spectrum, covering the three S+C+L bands, and potentially scalable to larger numbers of output fibers and routed channels.

Short Course of Antibiotic Therapy for Gram-Negative Bacilli Bacteremia in Patients with Cancer and Hematopoietic Stem Cell Transplantation: Less Is Possible.

Data about short courses of antibiotic therapy for Gram-negative bacilli (GNB) bacteremia in immunosuppressed patients are limited. This is a prospective observational study performed on adult patients with cancer and hematopoietic stem cell transplant (HSCT) who developed GNB bacteremia and received appropriate empirical antibiotic therapy (EAT), had a clinical response within 7 days and survived 48 h after the end of therapy. They received antibiotic therapy in the range of 7-15 days and were divided into short course, with a median of 7 days (SC), or long course, with a median of 14 days (LC).

Development of a Clinical Score to Stratify the Risk for Carbapenem-Resistant Enterobacterales Bacteremia in Patients with Cancer and Hematopoietic Stem Cell Transplantation.

Identifying the risk factors for carbapenem-resistant Enterobacterales (CRE) bacteremia in cancer and hematopoietic stem cell transplantation (HSCT) patients would allow earlier initiation of an appropriate empirical antibiotic treatment. This is a prospective multicenter observational study in patients from 12 centers in Argentina, who presented with cancer or hematopoietic stem-cell transplant and developed Enterobacterales bacteremia. A multiple logistic regression model identified risk factors for CRE bacteremia, and a score was developed according to the regression coefficient.

Experimental validation of machine-learning based spectral-spatial power evolution shaping using Raman amplifiers.

We experimentally validate a real-time machine learning framework, capable of controlling the pump power values of Raman amplifiers to shape the signal power evolution in two-dimensions (2D): frequency and fiber distance. In our setup, power values of four first-order counter-propagating pumps are optimized to achieve the desired 2D power profile. The pump power optimization framework includes a convolutional neural network (CNN) followed by differential evolution (DE) technique, applied online to the amplifier setup to automatically achieve the target 2D power profiles.

Optimized management of ultra-wideband photonics switching systems assisted by machine learning.

Recent years have seen an unprecedented growth of data traffic driven by a continuous increase of connected devices and new applications. This trend will tend to saturate transparent optical networks that are the backbone of the whole telecommunication infrastructure. To improve the capacity of already deployed network infrastructures and maximize operators CAPEX returns, band-division multiplexing (BDM) has emerged as a promising solution to expand the fiber bandwidth beyond the existing C-band.

Inverse design of a Raman amplifier in frequency and distance domains using convolutional neural networks.

We present a convolutional neural network architecture for inverse Raman amplifier design. This model aims at finding the pump powers and wavelengths required for a target signal power evolution in both distance along the fiber and in frequency. Using the proposed framework, the prediction of the pump configuration required to achieve a target power profile is demonstrated numerically with high accuracy in C-band considering both counter-propagating and bidirectional pumping schemes.

Simultaneous gain profile design and noise figure prediction for Raman amplifiers using machine learning.

A machine learning framework predicting pump powers and noise figure profile for a target distributed Raman amplifier gain profile is experimentally demonstrated. We employ a single-layer neural network to learn the mapping from the gain profiles to the pump powers and noise figures. The obtained results show highly accurate gain profile designs and noise figure predictions, with a maximum error on average of ∼0.

Tedizolid (torezolid) for the treatment of complicated skin and skin structure infections.

Introduction: Acute bacterial skin and skin structure infections (ABSSSI) are among the most frequent infectious diseases. Recently, several new antibiotics with activity against MRSA have been approved. Tedizolid, a second-generation oxazolidinone approved for ABSSSI offers theoretical advantages over first-generation oxazolidinones.

Proposal of a clinical score to stratify the risk of multidrug-resistant gram-negative rods bacteremia in cancer patients.

Introduction: Multidrug-resistant gram-negative rods (MDR GNR) represent a growing threat for patients with cancer. Our objective was to determine the characteristics of and risk factors for MDR GNR bacteremia in patients with cancer and to develop a clinical score to predict MDR GNR bacteremia.

Material And Methods: Multicenter prospective study analyzing initial episodes of MDR GNR bacteremia.

Enhanced resilience towards ROADM-induced optical filtering using subcarrier multiplexing and optimized bit and power loading.

In flexible optical networks, lightpaths are routed from source to destination thanks to reconfigurable optical add-drop multiplexers (ROADMs) placed in every node connected by a line system. As ROADMs are based on wavelength selective switches (WSSs), which imply channel filtering, a non negligible performance reduction can be observed when lightpaths traverse many network nodes. Control plane software network controllers that base their decision on the quality of transmission of the physical layer must also take into account the impact of ROADMs cascading.

Nonlinear mitigation on subcarrier-multiplexed PM-16QAM optical systems.

We report a comprehensive set of experimental, simulation and analytical results on the benefit of nonlinear mitigation strategies for multi-subcarrier (MSC) PM-16QAM transmission systems. First, we demonstrate ~9% maximum reach gain enabled by symbol-rate optimization (SRO) of MSC-PM-16QAM in a 31 channels WDM transmission experiment. Then, we demonstrate that, in the considered experimental scenario, the gain provided by digital backpropagation (DBP) over single-carrier (SC) transmission is similar to that achieved by SRO over MSC transmission.

[Levofloxacin prophylaxis in neutropenic patients].

Fluorquinolone-prophylaxis has proven useful in preventing infections in high risk neutropenic patients. The objective of this study was to describe the clinical, microbiological and therapeutic characteristics, and outcome of patients in the first episode of febrile neutropenia, comparing those who received levofloxacin prophylaxis with those who didn't. It was a prospective observational study that included all the episodes of inpatients with febrile neutropenia (February 1997- November 2014), also including the first episode in a same patient in different hospitalizations.

[Acute diarrhea after kidney or kidney-pancreas transplantation].

Diarrhea is a frequent and potentially severe complication of kidney transplantation. We describe here, in a cross-sectional study, the epidemiological and microbiological characteristics of acute and persistent diarrhea in 52 inpatients with kidney and kidney-pancreas transplant in a hospital in Buenos Aires, 42 (80.8%) of whom had received a kidney and 10 (19.

EGN model of non-linear fiber propagation.

The GN-model has been proposed as an approximate but sufficiently accurate tool for predicting uncompensated optical coherent transmission system performance, in realistic scenarios. For this specific use, the GN-model has enjoyed substantial validation, both simulative and experimental. Recently, however, it has been pointed out that its predictions, when used to obtain a detailed picture of non-linear interference (NLI) noise accumulation along a link, may be affected by a substantial NLI overestimation error, especially in the first spans of the link.

1306-km 20x124.8-Gb/s PM-64QAM transmission over PSCF with net SEDP 11,300 (b ∙ km)/s/Hz using 1.15 samp/symb DAC.

We demonstrated the transmission of a Nyquist-WDM signal based on PM-64QAM modulation in an EDFA-only submarine configuration composed of 54.4 km-long fiber spans: 20 channels at 124.8-Gb/s were propagated over 1306 km of low-loss pure-silica-core fiber (PSCF).

Extension and validation of the GN model for non-linear interference to uncompensated links using Raman amplification.

We show the extension of the Gaussian Noise model, which describes non-linear propagation in uncompensated links of multilevel modulation formats, to systems using Raman amplification. We successfully validate the analytical results by comparison with numerical simulations of Nyquist-WDM PM-16QAM channels transmission over multi-span uncompensated links made of a single fiber type and using hybrid EDFA/Raman amplification with counter-propagating pumps. We analyze two typical high- and low-dispersion fiber types.

Experimental demonstration of a frequency-domain Volterra series nonlinear equalizer in polarization-multiplexed transmission.

Employing 100G polarization-multiplexed quaternary phase-shift keying (PM-QPSK) signals, we experimentally demonstrate a dual-polarization Volterra series nonlinear equalizer (VSNE) applied in frequency-domain, to mitigate intra-channel nonlinearities. The performance of the dual-polarization VSNE is assessed in both single-channel and in wavelength-division multiplexing (WDM) scenarios, providing direct comparisons with its single-polarization version and with the widely studied back-propagation split-step Fourier (SSF) approach. In single-channel transmission, the optimum power has been increased by about 1 dB, relatively to the single-polarization equalizers, and up to 3 dB over linear equalization, with a corresponding bit error rate (BER) reduction of up to 63% and 85%, respectively.

SDF-1α degrades whereas glycoprotein 120 upregulates Bcl-2 interacting mediator of death extralong isoform: implications for the development of T cell memory.

After a primary immune response, T cell memory occurs when a subset of Ag-specific T cells resists peripheral selection by acquiring resistance to TCR-induced death. Recent data have implicated Bcl-2 interacting mediator of death (Bim) as an essential mediator of the contraction phase of T cell immunity. In this article, we describe that stromal-derived factor-1α (SDF-1α) ligation of CXCR4 on activated T cells promotes two parallel processes that favor survival, phospho-inactivation of Foxo3A, as well as Bim extralong isoform (Bim(EL)) degradation, both in an Akt- and Erk-dependent manner.

Novel figure of merit to compare fibers in coherent detection systems with uncompensated links.

We introduce an improved fiber figure of merit (FoM) in order to compare different fiber types used in uncompensated links for transmission of coherently-received modulation formats. The role of fiber dispersion in enhancing system performance is shown and verified by simulations and experiments, confirming the need for the inclusion of dispersion parameter in a FoM definition allowing to compare fiber types with relevant different dispersion parameters. Applicability of the proposed FoM has been demonstrated for channel spacing from the Nyquist limit up to 5/3 the symbol rate.

Experimental validation of an analytical model for nonlinear propagation in uncompensated optical links.

Link design for optical communication systems requires accurate modeling of nonlinear propagation in fibers. This topic has been widely analyzed in last decades with partial successes in special conditions, but without a comprehensive solution. Since the introduction of coherent detection with electronic signal processing the scenario completely changed because this category of systems shows better performances in links without in-line dispersion management.

Analytical results on channel capacity in uncompensated optical links with coherent detection.

Based on a recently introduced model of non-linear propagation, we propose analytical formulas for the capacity limit of polarization-multiplexed ultra-dense WDM uncompensated coherent optical systems at the Nyquist limit, assuming both lumped and ideally distributed amplification. According to these formulas, capacity fundamentally depends on the transmitted power spectral density and on the total optical WDM bandwidth, whereas it does not depend on symbol-rate. Also, capacity approximately decreases by 2 [bit/s/Hz] for every doubling of link length.