Sound emission and annihilations in a programmable quantum vortex collider.

In quantum fluids, the quantization of circulation forbids the diffusion of a vortex swirling flow seen in classical viscous fluids. Yet, accelerating quantum vortices may lose their energy into acoustic radiations1,2, similar to the way electric charges decelerate on emitting photons. The dissipation of vortex energy underlies central problems in quantum hydrodynamics3, such as the decay of quantum turbulence, highly relevant to systems as varied as neutron stars, superfluid helium and atomic condensates4,5. A deep understanding of the elementary mechanisms behind irreversible vortex dynamics has been a goal for decades3,6, but it is complicated by the shortage of conclusive experimental signatures7. Here we address this challenge by realizing a programmable vortex collider in a planar, homogeneous atomic Fermi superfluid with tunable inter-particle interactions. We create on-demand vortex configurations and monitor their evolution, taking advantage of the accessible time and length scales of ultracold Fermi gases8,9. Engineering collisions within and between vortex-antivortex pairs allows us to decouple relaxation of the vortex energy due to sound emission and that due to interactions with normal fluid (that is, mutual friction). We directly visualize how the annihilation of vortex dipoles radiates a sound pulse. Further, our few-vortex experiments extending across different superfluid regimes reveal non-universal dissipative dynamics, suggesting that fermionic quasiparticles localized inside the vortex core contribute significantly to dissipation, thereby opening the route to exploring new pathways for quantum turbulence decay, vortex by vortex.

Non-interactive effects drive multiple stressor impacts on the taxonomic and functional diversity of atlantic stream macroinvertebrates.

Freshwaters are considered among the most endangered ecosystems globally due to multiple stressors, which coincide in time and space. These local stressors typically result from land-use intensification or hydroclimatic alterations, among others. Despite recent advances on multiple stressor effects, current knowledge is still limited to manipulative approaches minimizing biological and abiotic variability. Thus, the assessment of multiple stressor effects in real-world ecosystems is required. Using an extensive survey of 50 stream reaches across North Portugal, we evaluated taxonomic and functional macroinvertebrate responses to multiple stressors, including marked gradients of nutrient enrichment, flow reduction, riparian vegetation structure, thermal stress and dissolved oxygen depletion. We analyzed multiple stressor effects on two taxonomic (taxon richness, Shannon-diversity) and two trait-based diversity indices (functional richness, functional dispersion), as well as changes in trait composition. We found that multiple stressors had additive effects on all diversity metrics, with nutrient enrichment identified as the most important stressor in three out of four metrics, followed by dissolved oxygen depletion and thermal stress. Taxon richness, Shannon-diversity and functional richness responded similarly, whereas functional dispersion was driven by changes in flow velocity and thermal stress. Functional trait composition changed along a major stress gradient determined by nutrient enrichment and oxygen depletion, which was positively correlated with organisms possessing fast-living strategies, aerial respiration, adult phases, and gathering-collector feeding habits. Overall, our results reinforce the need to consider complementary facets of biodiversity to better identify assembly processes in response to multiple stressors. Our data suggest that stressor interactions may be less frequent in real-word streams than predicted by manipulative experiments, which can facilitate mitigation strategies. By combining an extensive field survey with an integrative consideration of multiple biodiversity facets, our study provides new insights that can help to better assess and manage rivers in a global change context.

Tunneling Transport of Unitary Fermions across the Superfluid Transition.

We investigate the transport of a Fermi gas with unitarity-limited interactions across the superfluid phase transition, probing its response to a direct current (dc) drive through a tunnel junction. As the superfluid critical temperature is crossed from below, we observe the evolution from a highly nonlinear to an Ohmic conduction characteristic, associated with the critical breakdown of the Josephson dc current induced by pair condensate depletion. Moreover, we reveal a large and dominant anomalous contribution to resistive currents, which reaches its maximum at the lowest attained temperature, fostered by the tunnel coupling between the condensate and phononic Bogoliubov-Anderson excitations. Increasing the temperature, while the zeroing of supercurrents marks the transition to the normal phase, the conductance drops considerably but remains much larger than that of a normal, uncorrelated Fermi gas tunneling through the same junction. We attribute such enhanced transport to incoherent tunneling of sound modes, which remain weakly damped in the collisional hydrodynamic fluid of unpaired fermions at unitarity.

Serotonin and aggressive behaviour in children and adolescents: a systematic review.

OBJECTIVE: The role of serotonin (5-HT) in human aggression has been the subject of a large number of studies, mostly with adults. Meta-analyses indicate a small but significant inverse relationship between central nervous 5-HT availability and aggression, but genetically informed studies suggest two pathways: one to reactive aggression and the other to proactive aggression. METHOD: We conducted a systemic review on central nervous 5-HT function in children and adolescents, with attention to the function of aggression. RESULTS: In total, 675 articles were screened for relevance, with 45 reviewed. These included blood assays (e.g. plasma, 5-HIAA; platelet 5-HTR2A ), epigenetic studies, retrospective PET studies and 5-HT challenge paradigms (e.g. tryptophan depletion). Overall, findings were mixed, with support both for negative and for positive associations of central nervous 5-HT function with aggression in children and adolescents. CONCLUSION: We propose factors that may be blurring the picture, including problems in the conceptualization and measurement of aggression in young people, the lack of prospective designs and the bias towards clinical samples of boys. Research needs to account for variance in the both motivation for and implementation of aggression, and look to the behavioural economics literature to consider the roles of reward, vengeance and self-control more clearly.

Structural analyses of blended Nafion/PVDF electrospun nanofibers.

A new type of polymer blend, prepared by electrospinning nanofibers containing the immiscible polymers polyvinylidene fluoride (PVDF, 10 wt%) and Nafion® perfluorosulfonic acid (90 wt%), has been characterized experimentally. The internal nanofiber morphology is unique and unlike a normal blend, with individual phase-separated and randomly distributed fibrils of Nafion and PVDF (∼2-7 nm in diameter) that are bundled together and aligned in the fiber axis direction (where the fiber diameter is ∼500 nm). This morphology is retained when fiber mats are hot-pressed into dense films. The physicochemical properties of the electrospun blended fibers are also highly unusual and unanticipated. As shown in this study, each polymer component influences the thermal and structural behavior of the other, especially in the dry state. Thus, dry composite polymer mats and membranes exhibit properties and attributes that are not observed for either pure PVDF or pure Nafion. Experimental results indicate that: (i) PVDF imparts conformational constraints on the polytetrafluoroethylene (PTFE) backbone chains of Nafion, resulting in an increased 21 helical conformation that effects Nafion's water uptake and thermal properties; and (ii) dipole-dipole interactions between PVDF polymer chains and Nafion make the ß-phase polymorph of PVDF much more stable at elevated temperatures. Such "reciprocal templating" in electrospun fibers may not be unique to Nafion and PVDF, thus the procedure represents a new method of creating nanostructured multi-component polymer materials with innovative features.

Diffusion tensor imaging and tractography to evaluate sacral nerve root abnormalities in endometriosis-related pain: a pilot study.

OBJECTIVE: To prospectively evaluate microstructural abnormalities in sacral nerve roots in women affected by chronic pelvic pain associated with endometriosis. METHODS: We enrolled 30 women with an ultrasound diagnosis of endometriosis and moderate-severe chronic pelvic pain; 10 age-matched healthy women comprised the control group. All subjects underwent 3 T magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI); the sacral roots were reconstructed by post-processing the DTI data with dedicated software. Mean fractional anisotropy (FA) values in the S1, S2 and S3 roots were quantified. Analysis of FA values was performed by two radiologists in order to evaluate the interobserver agreement. RESULTS: The sacral nerve roots in healthy subjects were clearly visualised. Most of the patients with endometriosis displayed abnormalities of S1, S2 and S3 bilaterally at tractography, including an irregular and disorganised appearance. FA values in the S1, S2 and S3 roots were significantly lower in patients than in controls (P < 0.0001, <0.05 and <0.02, respectively) for both observers. No significant difference was found between observers. CONCLUSION: DTI with tractography is a non-invasive means of detecting changes in the microarchitecture of the sacral nerve roots. It can qualitatively and quantitatively reveal sacral root abnormalities in patients with endometriosis-associated pain. KEY POINTS: • MRI is increasingly used for endometriosis and chronic pelvic pain (CPP). • Magnetic resonance tractography can demonstrate microarchitectural abnormalities in sacral nerve roots. • Tractography shows altered microstructure of sacral roots affected by endometriosis and CPP. • S1-S3 fractional anisotropy values are lower in endometriosis than in healthy women. • Sacral nerve root alteration may explain the nature of endometriosis-related CPP.

Spatial accumulation of flood-driven riverside litter in two Northern Atlantic Rivers.

The escalation of litter accumulation in aquatic environments is recognized as an emerging global concern. Although rivers represent the main conduits for land-based waste into the oceans, the spatial dynamics of litter accumulation in these systems remain poorly investigated, especially after hydro-climatic extreme events. Floods have been identified as major drivers of litter mobilization, including macroplastics, within rivers. However, predicting flood-induced litter accumulation along riverbanks is complex due to the cumulative interplay of multiple environmental (geomorphological and riparian) and anthropogenic factors. Using empirical data collected from 14 stream reaches in two Northern Atlantic rivers in Portugal, our study evaluates which factors, among geomorphological, riparian, and anthropogenic descriptors, best drive riverside litter accumulation after floods. Taking into account the longitudinal gradient and the spatial heterogeneity of the studied reaches, our study enhances how the accumulation and characteristics (type, size) of riverside litter vary across a rural-urban continuum. Our model reveals that the combination of the human population density and the stream slope at river reach showed the highest explanatory power for the accumulation of riverside litter. Our findings indicate that litter tends to be retained close to the source, even under flood conditions. We also found that the structure of riparian vegetation showed low explanatory power for litter accumulation. However, riparian trapping could be influenced by litter input (density and type) which varies with anthropogenic activities. This work highlights the importance of gathering field data to identify critical areas of riverside litter accumulation within river basins. Our findings can further support environmental managers in designing and implementing effective cleanup campaigns and implementing plastic recovery strategies at specific areas. Nevertheless, it is crucial to enhance coordinated efforts across the entire value chain to reduce plastic pollution, promote innovative approaches for plastic litter valorization, and establish effective prevention pathways.

Hepsin in the diagnosis of prostate cancer.

AIM: In the current study we verified whether the expression of hepsin in prostate cancer (PCa) of samples obtained from radical retropubic prostatectomies (RRP) was significantly different from the adjacent normal prostatic tissue. METHODS. We evaluate the expression of hepsin by using immunohistochemistry in PCa tissue in respect to the adjacent normal tissue, of 18 patients who underwent RRP. RESULTS: Hepsin positive immunoreactivity was estimated on the staining intensity as negative (0), weakly positive (1+), moderately positive (2+), and strongly positive (3+). Hepsin immunoreactivity was detected in 100.0% PCa: 94.4% of cases showed a moderate/strong intensity, 5.6% a weak intensity. The adjacent benign prostatic tissue demonstrated a 83.3% of weak intensity, 11.1% had no reactivity and 5.6% were moderately intense. PCa demonstrated a significant higher (P<0.05) hepsin intensity (2.67) than the adjacent benign tissue (0.94). CONCLUSION: Hepsin should be regarded as a novel potential immunohistochemical marker for the histopathological diagnosis of PCa.

Remote sensing depicts riparian vegetation responses to water stress in a humid Atlantic region.

Riparian areas in the Cantabrian Atlantic ecoregion (northwest Portugal) play a key role in soil formation and conservation, regulation of nutrient and water cycle, creation of landscape aesthetic value and the preservation of biodiversity. The maintenance of their ecological integrity is crucial given the ever increase in multiple anthropogenic (water demand and agriculture) and climatic pressures (droughts and extreme events). We developed a transferable remote sensing approach, taking advantage of the latest freely available technologies (Sentinel-2 and Copernicus Land products), to detect intra-annual and inter-annual changes in riparian vegetation productivity at the river basin scale related to water stress. This study has used the normalized difference vegetation index (NDVI) to investigate riparian vegetation productivity dynamics on three different vegetation types (coniferous, broadleaved and grassland) over the past 5 years (2015-2019). Our results indicated that inter-annual seasonality differed between drier (2017) and wetter (2016) years. We found that intra-annual dynamics of NDVI were influenced by the longitudinal river zonation. Our model ranked first (r2m = 0.73) showed that the productivity of riparian vegetation during the dry season was positively influenced by annual rainfall and by the type of riparian vegetation. The emergent long lags between climatic variation and riparian plant productivity provides opportunities to forecast early warnings of climatically-driven impacts. In addition, the different average productivity levels among vegetation types should be considered when assessing climatic impacts on riparian vegetation. Future applications of Sentinel 2 products could seek to distinguish riparian areas that are likely to be more vulnerable to changes in the annual water balance from those that are more resistant under longer-term changes in climate.

Strongly correlated superfluid order parameters from dc Josephson supercurrents.

The direct-current (dc) Josephson effect provides a phase-sensitive tool for investigating superfluid order parameters. We report on the observation of dc Josephson supercurrents in strongly interacting fermionic superfluids across a tunneling barrier in the absence of any applied potential difference. For sufficiently strong barriers, we observed a sinusoidal current-phase relation, in agreement with Josephson's seminal prediction. We mapped out the zero-resistance state and its breakdown as a function of junction parameters, extracting the Josephson critical current behavior. By comparing our results with an analytic model, we determined the pair condensate fraction throughout the Bardeen-Cooper-Schrieffer-Bose-Einstein condensation crossover. Our work suggests that coherent Josephson transport may be used to pin down superfluid order parameters in diverse atomic systems, even in the presence of strong correlations.

Improvement of uterine artery Doppler velocimetry indices after metroplasty in arcuate uteri.

OBJECTIVE: Our study aimed to evaluate the effect of metroplasty performed in arcuate uteri on uterine artery Doppler velocimetry. STUDY DESIGN: We performed uterine artery Doppler velocimetry transvaginally before and after metroplasty in 36 women with arcuate uteri. Pulsatility indexes (PI) of uterine arteries were calculated and the presence or absence of a protodiastolic notch was evaluated. RESULTS: Comparing Doppler indexes before and after metroplasty, we found that uterine artery impedance improves as assessed by lower mean PI. We observed that PI after intervention was significantly lower compared with indexes before for mean Doppler index evaluations (mean uterine PI pre: 2.07+/-0.61 and post: 1.49+/-0.24 [p<0.03]). No differences were observed as regards bilateral protodiastolic notch absence or presence. A protodiastolic notch was present in 22 out of 36 women before metroplasty (61%), and a notch was observed in 19 out of 36 (52%) after metroplasty. CONCLUSIONS: Our results suggest that, metroplasty, as well as making the uterine cavity wider, leads to better uterine perfusion.

Septate uterus: reproductive outcome after hysteroscopic metroplasty.

OBJECTIVE: To evaluate hysteroscopic metroplasty and its effect on reproductive outcome. STUDY DESIGN: Seventy-five patients consulted for uterine septum between January 1996 to December 2000 at "La Sapienza" University in Rome were included in the study. RESULTS: Forty patients attempted pregnancy and a total of 30 spontaneous pregnancies resulted (75% pregnancy rate). The uterine cavity was normal at hysteroscopic follow-up in 68% of cases. CONCLUSION: Correction of uterine septum improves pregnancy outcome of patients. Broadening the indications for hysteroscopic metroplasty should be encouraged for patients who desire to conceive.

Epidermal-specific deletion of CD44 reveals a function in keratinocytes in response to mechanical stress.

CD44, a large family of transmembrane glycoproteins, plays decisive roles in physiological and pathological conditions. CD44 isoforms are involved in several signaling pathways essential for life such as growth factor-induced signaling by EGF, HGF or VEGF. CD44 is also the main hyaluronan (HA) receptor and as such is involved in HA-dependent processes. To allow a genetic dissection of CD44 functions in homeostasis and disease, we generated a Cd44 floxed allele allowing tissue- and time-specific inactivation of all CD44 isoforms in vivo. As a proof of principle, we inactivated Cd44 in the skin epidermis using the K14Cre allele. Although the skin of such Cd44Δker mutants appeared morphologically normal, epidermal stiffness was reduced, wound healing delayed and TPA induced epidermal thickening decreased. These phenotypes might be caused by cell autonomous defects in differentiation and HA production as well as impaired adhesion and migration on HA by Cd44Δker keratinocytes. These findings support the usefulness of the conditional Cd44 allele in unraveling essential physiological and pathological functions of CD44 isoforms.

Development and validation of an improved method for the determination of chloropropanols in paperboard food packaging by GC-MS.

The objective of this study was to develop an improved analytical method for the determination of 3-chloro-1,2-propanediol (3-MCPD) and 1,3-dichloropropanol (1,3-DCP) in paper-type food packaging. The established method includes aqueous extraction, matrix spiking of a deuterated surrogate internal standard (3-MCPD-d5), clean-up using Extrelut solid-phase extraction, derivatisation using a silylation reagent, and GC-MS analysis of the chloropropanols as their corresponding trimethyl silyl ethers. The new method is applicable to food-grade packaging samples using European Commission standard aqueous extraction and aqueous food stimulant migration tests. In this improved method, the derivatisation procedure was optimised; the cost and time of the analysis were reduced by using 10 times less sample, solvents and reagents than in previously described methods. Overall the validation data demonstrate that the method is precise and reliable. The limit of detection (LOD) of the aqueous extract was 0.010 mg kg(-1) (w/w) for both 3-MCPD and 1,3-DCP. Analytical precision had a relative standard deviation (RSD) of 3.36% for 3-MCPD and an RSD of 7.65% for 1,3-DCP. The new method was satisfactorily applied to the analysis of over 100 commercial paperboard packaging samples. The data are being used to guide the product development of a next generation of wet-strength resins with reduced chloropropanol content, and also for risk assessments to calculate the virtual safe dose (VSD).

The role of oxidative stress in HIV disease.

Evidence has accumulated suggesting that HIV-infected patients are under chronic oxidative stress. Perturbations to the antioxidant defense system, including changes in levels of ascorbic acid, tocopherols, carotenoids, selenium, superoxide dismutase, and glutathione, have been observed in various tissues of these patients. Elevated serum levels of hydroperoxides and malondialdehyde also have been noted and are indicative of oxidative stress during HIV infection. Indications of oxidative stress are observed in asymptomatic HIV-infected patients early in the course of the disease. Oxidative stress may contribute to several aspects of HIV disease pathogenesis, including viral replication, inflammatory response, decreased immune cell proliferation, loss of immune function, apoptosis, chronic weight loss, and increased sensitivity to drug toxicities. Glutathione may play a role in these processes, and thus, agents that replete glutathione may offer a promising treatment for HIV-infected patients. Clinical studies are underway to evaluate the efficacy of the glutathione-repleting agents, L-2-oxothiazolidine-4-carboxylic acid (OTC) and N-acetylcysteine (NAC), in HIV-infected patients.

Bi-quadratic surface response for quantitative determination of analytes leading to partially overlapped chromatographic peaks.

A simple analytic approach is described for the accurate determination of the concentration of components which give rise to partially overlapped chromatographic peaks. This method requires neither deconvolution processes nor chromatographic separation of the peaks. From the empirical point of view a bi-quadratic function has been found relating the area of an unresolved peak with the concentrations of the related analyte and of the interfering one. Such concentrations are then computed by solving the related non linear system of equations by the Newton-Raphson method.

Rapid expansion from supercritical to aqueous solution to produce submicron suspensions of water-insoluble drugs.

Stable suspensions of submicron particles of cyclosporine, a water-insoluble drug, have been produced by rapid expansion from supercritical to aqueous solution (RESAS). To minimize growth of the cyclosporine particles, which would otherwise occur in the free jet expansion, the solution was sprayed into an aqueous Tween-80 (Polysorbate-80) solution. Steric stabilization by the surfactant impedes particle growth and agglomeration. The particles were an order of magnitude smaller than those produced by RESS into air without the surfactant solution. Concentrations as high as 38 mg/mL for 400-700 nm particles were achieved in a 5.0% (w/w) Tween-80 solution.

Mixed-mechanism ionization to enhance sensitivity in atmospheric pressure ionization LC/MS.

A novel dual-mechanism ionization technique for LC/MS/MS has been observed, characterized and applied to the quantitation of a tertiary amine-containing drug compound in dog plasma. This mixed-mechanism ionization approach can improve the sensitivity of the pneumatically assisted electrospray experiment. Under conditions of higher than normal chromatographic flow and lower electrospray voltage, approximately a 4-fold increase in sensitivity was realized. A detection limit of 16 pg (45 fmol) on-column, and inter-day imprecision and inaccuracy of < 11 and < 15%, respectively, were obtained. A trade-off in concentration sensitivity in favor of ease of sample preparation was made to increase sample throughput. Although results strongly suggest that mixed-mechanism ionization is in operation, and that pneumatically assisted electrospray is a partial contributor to the overall ionization process, the exact nature of the second mechanism of ionization is unclear at this time.

Is Ace inhibitor treatment a possible cause of better cardiovascular remodelling in well functioning kidney transplant?

Diseases of the cardiovascular system are a common cause of death in renal transplanted patients. In this study we assessed the echocardiographic morphological and functional findings after renal transplantation of two homogenous groups of transplanted patients with normal renal function. The first (A) with spontaneously normotensive patients, the second (B) with moderate hypertension treated mainly with Ace inhibitors. Analysis of these data highlights two noteworthy results: the similar left ventricle hypertrophy found in both groups and the existence of better diastolic compliance among the hypertensive transplanted patients. If this is confirmed by studies currently in progress, the importance of Ace-inhibitors treatment in remodelling cardiac dysfunction after long term dialysis treatment might be seriously considered.