Correction to: Effects of hydrolyzed fish protein and autolyzed yeast as substitutes of fishmeal in the gilthead sea bream (Sparus aurata) diet, on fish intestinal microbiome.

An amendment to this paper has been published and can be accessed via the original article.

Effects of hydrolyzed fish protein and autolyzed yeast as substitutes of fishmeal in the gilthead sea bream (Sparus aurata) diet, on fish intestinal microbiome.

BACKGROUND: This study evaluated the effects of partial substitution of dietary fishmeal (FM) with either fish protein hydrolysate (FPH) or autolysed dried yeast (HiCell®, Biorigin, Brazil) on intestinal microbiota of gilthead sea bream (Sparus aurata). A total number of 720 fish of 122.18 ± 6.22 g were fed for 92 days with three different diets in triplicate (3 tanks/diet). A diet based on FM/vegetable meal was used as control. The other two diets were formulated by replacing FM with 5% of either FPH or HiCell®. To analyze the gut microbiota associated to autochthonous and allochthonous microbial communities, the Illumina MiSeq platform for sequencing of 16S rRNA gene and QIIME pipeline were used. RESULTS: A total number of 102 OTUs (operational taxonomic units) at 97% identity were identified in fish gut samples collected at the end of feeding trial. Fourteen OTUs constituted the core gut microbiota, i.e. those OTUs found in at least nine out of fifteen samples per group and shared regardless of the diet. Eight OTUs were assigned to Firmicutes represented by Lactobacillus, Staphylococcus, and Bacillus genera, and six to Proteobacteria phylum. Dietary dried yeast autolysate modulated the intestinal microbiota by promoting the growth of some beneficial bacteria. At order level, fish fed yeast showed an enrichment in Bacillales and Clostridiales as compared to the control group, whereas fish fed FPH showed a significantly lower amount of bacteria belonging to Alteromonadales and Enterobacteriales than the other two feeding groups. Although we did not observe any effect of 5% FM replacement with alternative nitrogen sources at phylum level, at lower taxonomical levels, the composition of gut microbiota, in terms of relative abundance of specific taxa, was significantly influenced by the dietary treatment. CONCLUSIONS: The metabarcoding analysis revealed a clearly intestinal microbiota modulation in response to dietary autolyzed yeast. The abundance of some beneficial bacteria, i.e. indigestible carbohydrate degrading- and SCFA producing bacteria, was positively affected. Autolysed dried yeast obtained by the fermentation of a strain of Saccharomyces cerevisiae could be a valid alternative protein source to FM as well as a valid functional ingredient for aquafeed production [corrected].

The course of asthma during pregnancy in a recent, multicase-control study on respiratory health.

BACKGROUND: Over the years it has been widely stated that approximately one-third of asthmatic women experience worsening of the disease during pregnancy. However, the literature has not been reviewed systematically and the meta-analytic reviews include old studies. This study aimed to examine whether the prevalence of worsening asthma during pregnancy is still consistent with prior estimate or it has been reduced. METHODS: A detailed Clinical Questionnaire on respiratory symptoms, medical history, medication, use of services, occupation, social status, home environment and lifestyle was administered to random samples of the Italian population in the frame of the Gene Environment Interactions in Respiratory Diseases (GEIRD) study. Only clinical data belong to 2.606 subjects that completed the clinical stage of the GEIRD study, were used for the present study. RESULTS: Out of 1.351 women, 284 self-reported asthma and 92 of them had at least one pregnancy. When we considered the asthma course during pregnancy, we found that 16 women worsened, 31 remained unchanged, 25 improved. Seven women had not the same course in the different pregnancies and 13 did not know. The starting age of ICS use almost overlaps with that of asthma onset in women with worsening asthma during pregnancy (19 years ± 1.4), unlike the other women who started to use ICS much later (30.3 years ± 12). In addition, the worsening of asthma was more frequent in women with an older age of onset of asthma (18 years ± 9 vs 13 years ± 10). Among women who completed the ACT during the clinical interview, the 50% of women who experienced worsening asthma during pregnancy (6/12) had an ACT score below 20. CONCLUSION: Asthma was observed to worsen during pregnancy in a percentage much lower to that generally reported in all the previous studies. There is still room in clinical practice to further reduce worsening of asthma during pregnancy by improving asthma control, with a more structured approach to asthma education and management prepregnancy.

Optical efficiency and gain dynamics of modelocked semiconductor disk lasers.

Compact optically pumped passively modelocked semiconductor disk lasers (SDLs) based on active quantum wells (QWs) such as vertical external-cavity surface-emitting lasers (VECSELs) or modelocked integrated external-cavity surface-emitting lasers (MIXSELs) are wavelength-versatile sources that offer a unique combination of gigahertz pulse repetition rates and short pulse durations. In this paper, we present record-short pulses of 184 fs from a gigahertz MIXSEL emitting at a center wavelength of 1048 nm. This result comes at the expense of low optical-to-optical pump efficiency (<1%) and average output power limited to 115 mW. We experimentally observe that shorter pulses significantly reduce the macroscopic gain saturation fluence and develop a QW model based on rate equations to reproduce the gain saturation behavior and quantitatively explain the VECSEL and MIXSEL modelocking performances. We identify spectral hole burning as the main cause of the reduced gain at shorter pulse durations, which in combination with the short lifetime of the excited carriers strongly reduces the optical pump efficiency. Our better understanding will help to address these limitations in future ultrafast SDL designs.

Improved SESAMs for femtosecond pulse generation approaching the kW average power regime.

We present semiconductor saturable absorber mirrors (SESAMs) that can potentially support femtosecond pulses from ultrafast thin disk lasers (TDLs) with high average power approaching the kW-power level and high pulse energy in the range of 100 µJ to 1 mJ at megahertz pulse repetition rates. For high-power operation, the SESAM parameters will ultimately limit the shortest pulse duration from a soliton mode-locked laser before mode locking instabilities such as multiple pulsing instabilities and continuous wave (cw) breakthrough start to occur. Currently shorter pulses are prevented due to the inverse saturable absorption that becomes stronger with shorter pulses and results in a shift of the "rollover" of the nonlinear SESAM reflectivity towards lower fluences. Here we discuss a novel SESAM design that addresses these issues and can be grown by metal-organic vapor phase epitaxy (MOVPE), an attractive epitaxial growth technology for manufacturing.

NET amyloidogenic backbone in human activated neutrophils.

Activated human neutrophils produce a fibrillar DNA network [neutrophil extracellular traps (NETs)] for entrapping and killing bacteria, fungi, protozoa and viruses. Our results suggest that the neutrophil extracellular traps show a resistant amyloidogenic backbone utilized for addressing reputed proteins and DNA against the non-self. The formation of amyloid fibrils in neutrophils is regulated by the imbalance of reactive oxygen species (ROS) in the cytoplasm. The intensity and source of the ROS signal is determinant for promoting stress-associated responses such as amyloidogenesis and closely related events: autophagy, exosome release, activation of the adrenocorticotrophin hormone/α-melanocyte-stimulating hormone (ACTH/α-MSH) loop and synthesis of specific cytokines. These interconnected responses in human activated neutrophils, that have been evaluated from a morphofunctional and quantitative viewpoint, represent primitive, but potent, innate defence mechanisms. In invertebrates, circulating phagocytic immune cells, when activated, show responses similar to those described previously for activated human neutrophils. Invertebrate cells within endoplasmic reticulum cisternae produce a fibrillar material which is then assembled into an amyloidogenic scaffold utilized to convey melanin close to the invader. These findings, in consideration to the critical role played by NET in the development of several pathologies, could explain the structural resistance of these scaffolds and could provide the basis for developing new diagnostic and therapeutic approaches in immunomediated diseases in which the innate branch of the immune system has a pivotal role.

Pulmonary involvement in patients with Marfan Syndrome.

AIM: Pulmonary involvement is not generally considered a main feature of Marfan syndrome, an autosomal connective tissue disorder caused by mutations in fibrillin 1. Thanks to the substantial progress in treatments, life expectation of these patients has been dramatically improved determining changes in different organ systems. The number of patients with pulmonary pathology may be higher than expected. Objective of the study was to evaluate the pulmonary involvement in all the patients referring to the largest Italian center for Marfan syndrome, assessing clinical examination and lung function tests. METHODS: Clinical history, spirometry, lung volumes and diffusing capacity have been assessed in 64 patients of our national referral center. RESULTS: None of the patients reported chronic respiratory symptoms. Fourteen percent reported a previous pneumothorax and 3 blebs and 45% had moderate to severe rib cage abnormalities. Twenty-three percent had cardiothoracic surgery. Two of the 19 patients with chest TC performed at our hospital were diagnosed with emphysema and were both non smoker; 7 had subpleural apical blebs. Only 37% of patients had normal lung function; 19% showed a restrictive pattern and 44% an obstructive pattern or an isolated diffusion impairment or an isolated hyperinflation. All patients with pneumothorax showed an obstructive pattern and diffusion impairment. CONCLUSION: In the absence of early respiratory symptoms, pulmonary abnormalities should be detected and monitored before they aggravate. Particular attention should be paid to prevent pneumothorax. Our results support the importance of lung volume determination to identify patients in which pulmonary parenchyma require a careful chest CT evaluation.

Decreased apoptosis in fatty livers submitted to subnormothermic machine-perfusion respect to cold storage.

Machine perfusion at subnormothermic temperature (20°C), MP20, was developed by Vairetti et al. and showed to afford a better preservation of fatty livers respect to traditional cold storage (CS) in terms of enzyme release into the perfusate and bile, glycogen stores, energy charge and oxidative stress. Here we investigated whether it also caused decreased cell death by apoptosis. Fatty and lean Zucker rats were submitted to MP20 or CS for 6 h and reperfused normothermically for 2 h. Apoptotic cells were revealed by immunohistochemistry of activated caspase-3 and M30 (new epitope on CK18 degraded by caspase-3) and by the TUNEL assay. Portal pressure was also determined. A statistically significant reduction of hepatocyte apoptosis, but especially of sinusoidal cells was determined for fatty livers submitted to MP20 respect to CS. Portal pressure was significantly lower after MP20 respect to CS. The reduction of sinusoidal cell death by apoptosis without need for anti-apoptotic therapies appears particularly positive since apoptotic sinusoidal cells hinder microcirculation in the sinusoids and are thrombogenic. These results further confirm the potential of MP20 for preserving fatty livers that would be otherwise discarded as grafts, and thus for increasing the donor pool for liver transplantation.

Highly efficient optically pumped vertical-emitting semiconductor laser with more than 20 W average output power in a fundamental transverse mode.

We have demonstrated an optically pumped vertical-external-cavity surface-emitting laser (OP-VECSEL) generating more than 20 W of cw output power in a fundamental transverse mode (M2 approximately 1.1) at 960 nm. The laser is highly efficient with a slope efficiency of 49%, a pump threshold of 4.4 W, and an overall optical-to-optical efficiency of 43%.

Mode-locked laser diode with an ultrafast integrated uni-traveling carrier saturable absorber.

A novel two-section integrated mode-locked laser diode (MLLD) with a separate ultrafast uni-traveling carrier (UTC) saturable absorber section and semiconductor optical amplifier gain section is demonstrated. The UTC absorber is composed of a thin p-InGaAsP absorbing layer and an intrinsic InGaAsP collecting layer. By confining the photoexcitation process to the thin highly doped absorbing layer, the diffusion-limited hole extraction process is greatly enhanced. The investigated MLLD produces 600 fs uncompressed optical pulses at a 42 GHz repetition rate.

2.1-W picosecond passively mode-locked external-cavity semiconductor laser.

We demonstrate an optically pumped passively mode-locked external-cavity semiconductor laser generating 4.7-ps pulses at 957 nm with as much as 2.1 W of average output power and a 4-GHz repetition rate. Compared with earlier results, the chirp of the pulses has been greatly reduced by use of an intracavity etalon. Apart from restricting the bandwidth, the etalon also helps optimize wavelength-dependent gain parameters and dispersion.

All-optical sampling with a monolithically integrated Mach-Zehnder interferometer gate.

An all-optical sampler consisting of a polarization-independent monolithic Mach-Zehnder interferometer with integrated semiconductor optical amplifiers and a temporal resolution of 1 ps is presented. As an example, a simple 320-Gbit/s pattern has been successfully sampled, demonstrating the functionality of this scheme for high-bit-rate waveform characterizations in light-wave systems.

Passively Q-switched 0.1-mJ fiber laser system at 1.53 mum.

We demonstrate a passively Q-switched fiber laser system generating pulses with as much as 0.1 mJ of pulse energy at 1.53 mum and a >1-kHz repetition rate. These results were achieved with a simple master oscillator-power amplifier scheme with a single pump source, realized with large-mode-area fiber and multiple reflections upon a semiconductor saturable-absorber mirror.

Passively Q-switched 1.34- mum Nd:YVO(4) microchip laser with semiconductor saturable-absorber mirrors.

We demonstrate a passively Q -switched diode-pumped 1.34- microm Nd:YVO(4) microchip laser. We achieved single-frequency, 230-ps pulses by using an InGaAsP semiconductor saturable-absorber mirror. We can vary the pulse width and the repetition rate from 230ps to 12ns and from 30 kHz to 4 MHz, respectively, by changing the design parameters of the saturable absorber, the thickness of the crystal, and the pump power.

Use of piracetam improves sickle cell deformability in vitro and in vivo.

Microsieving diluted suspensions of oxygenated sickle cell anaemia (HbSS) cells on polycarbonate filters shows that piracetam improves the red cell deformability in vitro. In vivo an oral intake of 160 mg/kg/day divided in four doses enhances the HbSS cell deformability as actively as it does in in vitro experiments. The drug is also able partially to restore the impaired deformability of physiologically deoxygenated HbSS cells. These findings are consistent with the results of clinical trials, which show that continuous treatment with piracetam reduces the incidence of vaso-occlusive crises in patients with sickle cell disease.