Electron-phonon superconductivity in C-doped topological nodal-line semimetal Zr5Pt3: a muon spin rotation and relaxation (μSR) study

In the present work, we demonstrate that C-doped Zr₅Pt₃is an electron-phonon superconductor (with critical temperatureT_C= 3.8 K) with a nonsymmorphic topological Dirac nodal-line semimetal state, which we report here for the first time. The superconducting properties of Zr₅Pt₃C_0.5have been investigated by means of magnetization, resistivity, specific heat, and muon spin rotation and relaxation (μSR) measurements. We find that at low temperatures, the depolarization rate is almost constant and it can be well described by a single-bands-wave model with a superconducting gap of 2Δ(0)/k_BT_C= 3.84, somewhat higher than the value of BCS theory. From the transverse field μSR analysis, we estimate the London penetration depthλ_L= 469 nm, superconducting carrier densityn_s= 1.83 × 10²⁶ m^-3, and effective massm* = 1.428m_e. The zero field μSR confirms the absence of any spontaneous magnetic field in the superconducting ground state. In order to gain additional insights into the electronic ground state of C-doped Zr₅Pt₃, we also performed first-principles calculations within the framework of density functional theory (DFT). The observed homogenous electronic character of the Fermi surface as well as the mutual decrease ofT_Cand density of states at the Fermi level are consistent with the experimental findings of this study. However, the band structure reveals the presence of robust, gapless fourfold-degenerate nodal lines protected by 6₃screw rotations and glide mirror planes. Therefore, Zr₅Pt₃represents a novel, unprecedented condensed matter system to investigate the intricate interplay between superconductivity and topology.

COVID-19 Dashboard for the Lisbon Region - an advisory tool for policy

Issue/problem

At the time of arrival of the COVID-19 pandemic to Portugal, the Public Health Department of Lisbon and Tagus Valley Regional Health Administration was confronted with its obsolete information system, which could not provide the information that Public Health Authorities needed to bring the pandemic under control. In order to tackle this issue, our goal was to aggregate all the relevant epidemiological data for the region in an accessible and user-friendly dashboard.

Methods

Starting from March 2020 we created a dashboard, which compiled and analyzed COVID-19 data, such as: confirmed and active cases, deaths, hospitalizations (including ICU beds), high/low risk contacts, mandatory confinements, tests, and clusters. This dashboard had anonymized data and was updated daily as well as constantly upgraded by taking into consideration new incoming data and feedback provided by users, serving its purpose as an advisory tool for policy.

Results

The dashboard was available to Local, Regional, and National Public Health Authorities and made possible to monitor trends and predict epidemiological changes that, prior to its existence, were dispersed in several datasets. Most importantly, it allowed for a better allocation of human resources for contact tracing and case management activities, to easily identify basic social needs for the most vulnerable citizens. It also provided for policy measures adjusted to the smallest administrative division in Portugal, the parish, that ultimately allowed for a better epidemiological control in Lisbon Metropolitan Area in 2020.

Lessons

The regional dashboard is far from perfect, but it highlights the constant need for robust information and epidemiological surveillance systems, serving both National, Regional and Local Public Health Authorities. It appeared out of necessity during a pandemic and it proved once more the importance of data analytics for guiding public health action based on evidence.

Key messages

Data analytics can serve both as an advisory tool for policy as well as to guide public health interventions. The COVID-19 Dashboard for the Lisbon Region aggregates relevant epidemiological data that helped Public Health authorities better understand and control the Pandemic in the region.

Vitamin D supplementation improves the metabolic syndrome risk profile in postmenopausal women

Objective: This study aimed to evaluate the effect of isolated vitamin D (VD) supplementation on the metabolic syndrome (MetS) risk profile in postmenopausal women.Methods: In this double-blind, placebo-controlled trial, 160 postmenopausal women aged 50-65 years were randomized into two groups: VD group, supplementation with 1000 IU vitamin D₃/day (n = 80); or placebo group (n = 80). The intervention time was 9 months, and the women were assessed at baseline and endpoint. Clinical and anthropometric data were collected. Biochemical parameters, including total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, glucose, and insulin, were measured. The plasma concentration of 25-hydroxyvitamin D (25(OH)D) was measured by high-performance liquid chromatography.Results: After 9 months, there was a significant increase in the 25(OH)D levels for VD group (+45.4%, p < 0.001), and a decrease (-18.5%, p = 0.049) in the placebo group. In the VD group, a significant reduction was observed in triglycerides (-12.2%, p = 0.001), insulin (-13.7%, p = 0.008), and the homeostasis model assessment of insulin resistance (-17.9%, p = 0.007). In the placebo group, there was an increase in glucose (+6.2%, p = 0.009). Analysis of the risk adjusted for age, time since menopause, and body mass index showed that women supplemented with VD had a lower risk of MetS (odds ratio [OR] 0.42; 95% confidence interval [CI] 0.21-0.83), hypertriglyceridemia (OR 0.43; 95% CI 0.22-0.85), and hyperglycemia (OR 0.23; 95% CI 0.10-0.52) compared to the placebo group (p < 0.05).Conclusions: In postmenopausal women with VD deficiency, isolated supplementation with 1000 IU vitamin D₃ for 9 months was associated with a reduction in the MetS risk profile. Women undergoing VD supplementation had a lower risk of MetS, hypertriglyceridemia, and hyperglycemia.

Antidepressants in a changing ocean: Venlafaxine uptake and elimination in juvenile fish (Argyrosomus regius) exposed to warming and acidification conditions

The presence of antidepressants, such as venlafaxine (VFX), in marine ecosystems is increasing, thus, potentially posing ecological and human health risks. The inherent mechanisms of VFX uptake and elimination still require further understanding, particularly accounting for the impact of climate change-related stressors, such as warming and acidification. Hence, the present work aimed to investigate, for the first time, the effects of increased seawater temperature (ΔT°C = +5 °C) and pCO₂ levels (ΔpCO₂ ∼1000 μatm, equivalent to ΔpH = -0.4 units) on the uptake and elimination of VFX in biological tissues (muscle, liver, brain) and plasma of juvenile meagre (Argyrosomus regius) exposed to VFX through two different exposure pathways (via water, i.e. [VFX ] ∼20 μg L^-1, and via feed, i.e. [VFX] ∼160 μg kg^-1 dry weight, dw). Overall, results showed that VFX can be uptaken by fish through both water and diet. Fish liver exhibited the highest VFX concentration (126.7 ± 86.5 μg kg^-1 and 6786.4 ± 1176.7 μg kg^-1 via feed and water exposures, respectively), as well as the highest tissue:plasma concentration ratio, followed in this order by brain and muscle, regardless of exposure route. Both warming and acidification decreased VFX uptake in liver, although VFX uptake in brain was favoured under warming conditions. Conversely, VFX elimination in liver was impaired by both stressors, particularly when acting simultaneously. The distinct patterns of VFX uptake and elimination observed in the different scenarios calls for a better understanding of the effects of exposure route and abiotic conditions on emerging contaminants' toxicokinetics.

Differential behavioural responses to venlafaxine exposure route, warming and acidification in juvenile fish (Argyrosomus regius)

Antidepressants, such as venlafaxine (VFX), which are considered emerging environmental pollutants, are increasingly more present in the marine environment, and recent evidence suggest that they might have adverse effects on fish behaviour. Furthermore, altered environmental conditions associated to climate change (e.g. warming and acidification) can also have a determinant role on fish behaviour, fitness and survival. Yet, the underlying interactions between these environmental stressors (pharmaceuticals exposure and climate change) are still far from being fully understood. The aim of this study was to assess behavioural responses (in juvenile meagre (Argyrosomus regius) exposed to VFX via water ([VFX] ~20μgL^-1) and via dietary sources ([VFX] ~160μgkg^-1 dry weight), as well as to increased temperature (ΔT°C=+5°C) and high CO₂ levels (ΔpCO₂ ~1000μatm; equivalent to ΔpH=-0.4units). Overall, VFX bioaccumulation in fish plasma was enhanced under the combination of warming and acidification. VFX triggered fish exploration, whereas fish activity and shoal cohesion were reduced. Acidification alone decreased fish exploration and shoal cohesion, and reversed fish preference to turn leftwards compared to control conditions. Such alterations were further enhanced by VFX exposure. The combination of warming and acidification also reduced shoal cohesion and loss of lateralization, regardless of VFX exposure. The distinct behaviour observed when VFX contamination, acidification and warming acted alone or in combination highlighted the need to consider the likely interactive effects of seawater warming and acidification in future research regarding the toxicological aspects of chemical contaminants.

Integrated multi-biomarker responses of juvenile seabass to diclofenac, warming and acidification co-exposure

Pharmaceutical drugs, such as diclofenac (DCF), are frequently detected in the marine environment, and recent evidence has pointed out their toxicity to non-target marine biota. Concomitantly, altered environmental conditions associated with climate change (e.g. warming and acidification) can also affect the physiology of marine organisms. Yet, the underlying interactions between these environmental stressors (pharmaceutical exposure and climate change-related stressors) still require a deeper understanding. Comprehending the influence of abiotic variables on chemical contaminants' toxicological attributes provides a broader view of the ecological consequences of climate change. Hence, the aim of this study was to assess the ecotoxicological responses of juvenile seabass Dicenthrachus labrax under the co-exposure to DCF (from dietary sources, 500 ± 36 ng kg^-1 dw), warming (ΔTºC = +5 °C) and acidification (ΔpCO₂ ∼1000 μatm, equivalent to ΔpH = -0.4 units), using an "Integrated Biomarker Response" (IBR) approach. Fish were exposed to these three stressors, acting alone or combined, for 28 days in a full cross-factorial design, and blood, brain, liver and muscle tissues were subsequently collected in order to evaluate: i) animal/organ fitness; ii) hematological parameters and iii) molecular biomarkers. Results not only confirmed the toxicological attributes of dietary exposure to DCF in marine fish species at the tissue (e.g. lower HSI), cellular (e.g. increased ENAs and lower erythrocytes viability) and molecular levels (e.g. increased oxidative stress, protein degradation, AChE activity and VTG synthesis), but also showed that such attributes are altered by warming and acidification. Hence, while acidification and/or warming enhanced some effects of DCF exposure (e.g. by further lowering erythrocyte viability, and increasing brain GST activity and Ub synthesis in muscle), the co-exposure to these abiotic stressors also resulted in a reversion/inhibition of some molecular responses (e.g. lower CAT and SOD inhibition and VTG synthesis). IBRs evidenced that an overall higher degree of stress (i.e. high IBR index) was associated with DCF and warming co-exposure, while the effects of acidification were less evident. The distinct responses observed when DCF acted alone or the animals were co-exposed to the drug together with warming and acidification not only highlighted the relevance of considering the interactions between multiple environmental stressors in ecotoxicological studies, but also suggested that the toxicity of pharmaceuticals can be aggravated by climate change-related stressors (particularly warming), thus, posing additional biological challenges to marine fish populations.

Ecophysiological responses of juvenile seabass (Dicentrarchus labrax) exposed to increased temperature and dietary methylmercury

The ecotoxicological effects of methylmercury (MeHg) exposure have been intensively described in literature. Yet, it is still unclear how marine biota will respond to the presence of MeHg under climate change, namely ocean warming. The present study aimed to investigate, for the first time, fish condition [Fulton's K index (K), hepatosomatic index (HIS) and brain-to-body mass ratio (BB-ratio)] and several stress-related responses in an ecologically and commercially important fish species (Dicentrachus labrax) exposed for 28days to dietary MeHg (8.0mg kg-1 dw) and temperature increase (+4°C). Results showed significant impairments on fish condition, i.e. up to 34% decrease on K, >100% increase on HIS and 44% decrease on BB-ratio, compared to control conditions. Significant changes on tissue biochemical responses were observed in fish exposed to both stressors, acting alone or combined, evidencing the relevance of assessing possible interactions between different environmental stressors in ecotoxicological studies. For instance, muscle showed to be the least affected tissue, only revealing significant alterations in GST activity of MeHg-enriched fish. On the other hand, liver exhibited a significant induction of GST (>100%) and CAT (up to 74%) in MeHg-enriched fish, regardless of temperature exposure, as well as decreased SOD activity (19%) and increased HSP70/HSC70 content (87%) in fish exposed to warming alone. Brain showed to be affected by temperature (69% of GST inhibition and >100% of increased CAT activity), MeHg (>100% of increased CAT activity, 47% of SOD inhibition and 55% of AChE inhibition), as well as by the combination of both (GST, SOD and AChE inhibition, 17%, 48% and 53%, respectively). Hence, our data provides evidences that the toxicological aspects of MeHg ca be potentiated by warmer temperatures, thus, evidencing the need for further research combining contaminants exposure and climate change effects, to better forecast ecological impacts in the ocean of tomorrow.

Sinus histiocytosis with massive lymphadenopathy and malignant lymphoma. An unreported association

Sinus histiocytosis with massive lymphadenopathy is a benign disorder often characterized by spontaneous remission. Although immunologic abnormalities are common and high Epstein Barr virus titers have been reported, to date no case has been associated with malignant lymphoma. The authors report here the first case of this association.

Iatrogenic and idiopathic acute myelogenous leukemia: a comparison of clinical features and treatment complications

We have compared the clinical and laboratory features as well as treatment complications observed in 6 patients with iatrogenic acute myelogenous leukemia (I-AML) with those of 26 patients with idiopathic acute myelogenous leukemia (AML). I-AML patients were significantly younger and their disease appeared less virulent on admission than in the AML patients. Following identical chemotherapy, hemorrhagic complications and the need for platelet support were found to be similar for both groups. Major infections, including systemic candidiasis and Gram-negative septicemias, occurred 3 times more frequently among I-AML than AML patients. More marked suppression and delayed regeneration of the bone marrow also occurred in I-AML patients. These observations and other factors, such as post-splenectomy state and inherent immune deficiency among surgically staged lymphoma patients as well as radiation induced immunologic impairment, may have contributed to the increased propensity to develop infection observed in this group of patients. Five of the 6 I-AML and 17 of the 26 AML patients achieved remission. We attribute the satisfactory outcome in our I-AML patients to treatment in a protective environment and availability of facilities for hematologic supportive care.

Central nervous system involvement at presentation in acute granulocytic leukemia. A prospective cytocentrifuge study

We have undertaken a perspective study of the prevelance of the central nervous disease in acute granulocytic leukemia (AGL). Thirty-nine newly diagnosed patients with AGL underwent cytocentrifuge examination of cerebral spinal fluid. Seven of the 39 patients had blast cells in their cerebral spinal fluid. All seven of these patients had acute myelomonocytic leukemia (AMML). No patients with other variants of AGL demonstrated blast cells in their cerebral spinal fluid. Other high risk factors associated with meningeal infiltration were elevated serum lysozyme levels, high peripheral white blood cell count, low age, splemomegaly and the presence of infiltration in other organs. The admission rates for patients with meningeal leukemia were lower and the survival time was shorter than in both the 32 noninvolved patients and the noninvolved patients with AMML. We believe that a lumbar puncture is indicated in all patients with newly diagnosed AMML.