Multipoint-to-point data aggregation using a single receiver and frequency-multiplexed intensity-modulated ONUs

We demonstrate 2.5-GHz-spaced frequency multiplexing capable of aggregating 64 intensity-modulated end-users using low-speed electronic and optoelectronic components. All optical network units (ONUs) achieved high per-user capacity with dedicated optical bands, enabling future low latency applications

49 Gbit/s Direct-Modulation and Direct-Detection Transmission over 80 km SMF-28 without Optical Amplification or Filtering

We demonstrate direct-modulation of a discrete mode laser using Discrete Multi-Tone modulation for transmission distances up to 100 km in the 1550 nm band. A large operational temperature range (0-65ºC) is also demonstrated

Optical Injection-Locked Directly-Modulated Lasers for Dispersion Pre-compensated Direct-Detection Transmission

The growing traffic demand in inter-data center and metro communications requires high-speed and low-cost transceivers that can flexibly adapt to different transmission distances of up to a few hundred km. Ultimately low-cost transceivers will use the simplest optical hardware: namely a directly-modulated transmitter and direct detection receiver. Using optical injection-locked directly-modulated lasers (OIL-DML), we propose a transmitter that can control the full field of the optical signal and achieve error-free transmission over up to 300 km of dispersion uncompensated SMF-28. We demonstrate such a transmission system and discuss its potential for short and medium reach communication systems

Modulator-free quadrature amplitude modulation signal synthesis

The ability to generate high-speed on–off-keyed telecommunication signals by directly modulating a semiconductor laser’s drive current was one of the most exciting prospective applications of the nascent field of laser technology throughout the 1960s. Three decades of progress led to the commercialization of 2.5 Gbit s−1-per-channel submarine fibre optic systems that drove the growth of the internet as a global phenomenon. However, the detrimental frequency chirp associated with direct modulation forced industry to use external electro-optic modulators to deliver the next generation of on–off-keyed 10 Gbit s−1 systems and is absolutely prohibitive for today’s (>)100 Gbit s−1 coherent systems, which use complex modulation formats (for example, quadrature amplitude modulation). Here we use optical injection locking of directly modulated semiconductor lasers to generate complex modulation format signals showing distinct advantages over current and other currently researched solutions

In-hospital interstage improves interstage survival after the Norwood stage 1 operation.

OBJECTIVES: The interstage mortality rate after a Norwood stage 1 operation remains 12-20% in current series. In-hospital interstage facilitates escalation of care, possibly improving outcome. METHODS: A retrospective study was designed for hypoplastic left heart syndrome (HLHS) and HLHS variants, offering an in-hospital stay after the Norwood operation until the completion of stage 2. Daily and weekly examinations were conducted systematically, including two-dimensional and speckle-tracking echocardiography. Primary end points included aggregate survival until the completion of stage 2 and interstage freedom from escalation of care. Moreover, we calculated the sensitivity and specificity of speckle-tracking echocardiographic myocardial deformation in predicting death/transplant after the Norwood procedure. RESULTS: Between 2015 and 2019, 33 neonates with HLHS (24) or HLHS variants (9) underwent Norwood stage 1 (31) or hybrid palliation followed by a comprehensive stage 2 operation (2). Stage 1 Norwood-Sano was preferred in 18 (54.5%) neonates; the classic Norwood with Blalock-Taussig shunt was performed in 13 (39.4%) neonates. The Norwood stage 1 30-day mortality rate was 6.2%. The in-hospital interstage strategy was implemented after Norwood stage 1 with a 3.4% interstage mortality rate. The aggregate Norwood stage 1 and interstage Kaplan-Meier survival rate was 90.6 ± 5.2%. Escalation of care was necessary for 5 (17.2%) patients at 2.5 ± 1.2 months during the interstage for compromising atrial arrhythmias (2), Sano-shunt stenosis (1) and pneumonia requiring a high-frequency oscillator (2); there were no deaths. A bidirectional Glenn (25) or a comprehensive-Norwood stage 2 (2) was completed in 27 patients at 4.7 ± 1.2 months with a 92.6% survival rate. The overall Kaplan-Meier survival rate is 80.9 ± 7.0% at 4.3 years (mean 25.3 ± 15.7 months). An 8.7% Δ longitudinal strain 30 days after Norwood stage 1 had 100% sensitivity and 81% specificity for death/transplant. CONCLUSIONS: In-hospital interstage facilitates escalation of care, which seems efficacious in reducing interstage Norwood deaths. A significant reduction of longitudinal strain after Norwood stage 1 is a strong predictor of poor outcome

Influence of organic versus inorganic dietary selenium supplementation on the concentration of selenium in colostrum, milk and blood of beef cows

<p>Abstract</p> <p>Background</p> <p>Selenium (Se) is important for the postnatal development of the calf. In the first weeks of life, milk is the only source of Se for the calf and insufficient level of Se in the milk may lead to Se deficiency. Maternal Se supplementation is used to prevent this.</p> <p>We investigated the effect of dietary Se-enriched yeast (SY) or sodium selenite (SS) supplements on selected blood parameters and on Se concentrations in the blood, colostrum, and milk of Se-deficient Charolais cows.</p> <p>Methods</p> <p>Cows in late pregnancy received a mineral premix with Se (SS or SY, 50 mg Se per kg premix) or without Se (control – C). Supplementation was initiated 6 weeks before expected calving. Blood and colostrum samples were taken from the cows that had just calved (Colostral period). Additional samples were taken around 2 weeks (milk) and 5 weeks (milk and blood) after calving corresponding to Se supplementation for 6 and 12 weeks, respectively (Lactation period) for Se, biochemical and haematological analyses.</p> <p>Results</p> <p>Colostral period. Se concentrations in whole blood and colostrum on day 1 <it>post partum </it>and in colostrum on day 3 <it>post partum </it>were 93.0, 72.9, and 47.5 μg/L in the SY group; 68.0, 56.0 and 18.8 μg/L in the SS group; and 35.1, 27.3 and 10.5 μg/L in the C group, respectively. Differences among all the groups were significant (<it>P </it>< 0.01) at each sampling, just as the colostrum Se content decreases were from day 1 to day 3 in each group. The relatively smallest decrease in colostrum Se concentration was found in the SY group (<it>P </it>< 0.01).</p> <p>Lactation period. The mean Se concentrations in milk in weeks 6 and 12 of supplementation were 20.4 and 19.6 μg/L in the SY group, 8.3 and 11.9 μg/L in the SS group, and 6.9 and 6.6 μg/L in the C group, respectively. The values only differed significantly in the SS group (<it>P </it>< 0.05). The Se concentrations in the blood were similar to those of cows examined on the day of calving. The levels of glutathione peroxidase (GSH-Px) activity were 364.70, 283.82 and 187.46 μkat/L in the SY, SS, and C groups, respectively. This was the only significantly variable biochemical and haematological parameter.</p> <p>Conclusion</p> <p>Se-enriched yeast was much more effective than sodium selenite in increasing the concentration of Se in the blood, colostrum and milk, as well as the GSH-Px activity.</p

Nonlinearity-free Coherent Transmission in Hollow-Core Antiresonant Fiber

We demonstrate the first multi-terabit/s WDM data transmission through hollow-core antiresonant fiber (HC-ARF). 16 channels of 32-GBd dual-polarization (DP) Nyquist-shaped 256QAM signal channels were transmitted through a 270-m long fiber without observing any power penalty. In a single-channel high power transmission experiment, no nonlinearity penalty was observed for up to 1 W of received power, despite the very low chromatic dispersion of the fiber (<2 ps/nm/km). Our simulations show that such a low level of nonlinearity should enable transmission at 6.4 Tb/s over 1200 km of HC-ARF, even when the fiber attenuation is significantly greater than that of SMF-28. As signals propagate through hollow-core fibers at close to the speed of light in vacuum such a link would be of interest in latency-sensitive data transmission applications

Nucleophilic Functionalization of the Calix[6]arene Para- and Meta-Position via p‑Bromodienone Route

It is here demonstrated that the p-bromodienone route, previously reported for calix[4]arenes, is also effective for the functionalization of the calix[6]arene macrocycle. Thus, alcoholic O-nucleophiles can be introduced at the calix[6]arene exo rim. In addition, the reaction of a calix[6]arene p-bromodienone derivative with an actived aromatic substrate, such as resorcinol, led to the first example of a meta-functionalized, inherently chiral calix[6]arene derivativ

Targeting of PI3K/AKT/mTOR pathway to inhibit T cell activation and prevent graft-versus-host disease development

Producción CientíficaBackground: Graft-versus-host disease (GvHD) remains the major obstacle to successful allogeneic hematopoietic stem cell transplantation, despite of the immunosuppressive regimens administered to control T cell alloreactivity. PI3K/AKT/mTOR pathway is crucial in T cell activation and function and, therefore, represents an attractive therapeutic target to prevent GvHD development. Recently, numerous PI3K inhibitors have been developed for cancer therapy. However, few studies have explored their immunosuppressive effect. Methods: The effects of a selective PI3K inhibitor (BKM120) and a dual PI3K/mTOR inhibitor (BEZ235) on human T cell proliferation, expression of activation-related molecules, and phosphorylation of PI3K/AKT/mTOR pathway proteins were analyzed. Besides, the ability of BEZ235 to prevent GvHD development in mice was evaluated. Results: Simultaneous inhibition of PI3K and mTOR was efficient at lower concentrations than PI3K specific targeting. Importantly, BEZ235 prevented naïve T cell activation and induced tolerance of alloreactive T cells, while maintaining an adequate response against cytomegalovirus, more efficiently than BKM120. Finally, BEZ235 treatment significantly improved the survival and decreased the GvHD development in mice. Conclusions: These results support the use of PI3K inhibitors to control T cell responses and show the potential utility of the dual PI3K/mTOR inhibitor BEZ235 in GvHD prophylaxis.Asociación Española Contra el Cáncer (Proyecto AIOA110296BLAN).Gerencia Regional de Salud de Castilla y León (Proyecto GRS 726/A13