Antiphospholipid Antibodies in Sickle Cell Disease: A Systematic Review and Exploratory Meta-Analysis

The relationship between antiphospholipid antibodies (aPL) and sickle cell disease (SCD) has never been systematically addressed. Our aim was to evaluate potential links between SCD and aPL in all age groups. EMBASE/PubMed was screened from inception to May 2020 and Peto odds ratios for rare events were calculated. The pooled prevalence (PP) of IgG anticardiolipin antibodies (aCL) was higher in individuals with SCD than in controls (27.9% vs 8.7%, P < 0.0001), that of IgM aCL was similar in the two groups (2.9% vs 2.7%); only individuals with SCD were positive for lupus anticoagulant (LA) (7.7% vs 0%, P < 0.0001). The PP of leg ulcers was similar between aPL positive and negative individuals (44% vs 53%) and between patients in acute crisis and stable patients (5.6% vs 7.3%). Reporting of aPL as a binary outcome and not as a titer precluded further interpretation. The results indicate that a prospective case-control study with serial measurements of a panel of aPL in SCD patients might be warranted, in order to understand further the possible pathogenic role of aPL in SCD.

Cell aggregation on nanorough surfaces

The ability to control adhesion and the spatial organization of cells over nanoscale surfaces is essential in tissue engineering, regenerative medicine, the growth of organoids and spheroids as an in-vitro-model of human development and disease. Nonetheless, despite the several different works that have explored the influence of nanotopography on cell adhesion and clustering, little is known about how the forces arising from membrane conformational change developing during cell adaptation to a nanorough surface, and the cell-cell adhesion forces, interact to guide cell assembly. Here, starting from the works of Decuzzi and Ferrari, who examined how the energy of a cell varies while adhering to a nanoscale surface, and of Armstrong and collaborators, who developed a continuous model of cell-cell adhesion and morphogenesis, we provide a description of how nanotopography can modulate cellular clustering. In simulations where the parameters of the model were varied over large intervals, we found that nanoroughness may induce cell aggregation from a homogenous, uniform state, also for weak cell-cell adhesion. Results of the model are relevant in bio-engineering and biomedical nanotechnology, and may be of interest for those involved in the design and fabrication of biomaterials and scaffolds for tissue formation and repair.

Prognostic value of NT-proBNP and best cut-offs for risk prediction in obese patients with chronic systolic heart failure

Background

N-terminal fraction of pro-B-type natriuretic peptide (NT-proBNP) is a strong predictor of outcome in chronic systolic heart failure (CHF). Although plasma NT-proBNP has been reported to display an inverse correlation with body-mass-index (BMI), its prognostic value in obese patients has been poorly investigated so far.

Objectives

To evaluate the prognostic value and the best cut-offs for risk prediction of NT-proBNP in obese individuals from a multinational cohort of patients with systolic CHF.

Methods

We analyzed data from the BIOS (Biomarkers In Heart Failure Outpatient Study) Consortium. Patients with left ventricular ejection fraction (LVEF) ≤50% were selected and classified as nonobese (BMI &lt;30 kg/m2), mildly obese (BMI 30–35 kg/m2), moderately obese (BMI 35–40 kg/m2), or severely obese (BMI ≥40 kg/m2), according to standard nomenclature. Clinical and bio-humoral data, including NT-proBNP testing, were retrieved, and 5-year cardiac and all-cause mortality status were considered as primary and secondary outcome, respectively. The independent prognostic role of NT-proBNP was evaluated through Cox regression analysis, adjusting the model for age, gender, New York Heart Association class, ischaemic aetiology, LVEF, and estimated glomerular filtration rate (eGFR).

Results

The study population included 11,574 patients (age 65±12 years, LVEF 30±9%, males 78%). Most of patients were nonobese (n=8,937, 77%), while mildly, moderately, and severely obese patients were 1,887 (16%), 499 (4%), and 251 (3%), respectively. Median values of plasma NT-proBNP were progressively lower from nonobese to mildly, moderately, and severely obese patients (1455 ng/L, 903 ng/L, 767 ng/L, 660 ng/L, respectively) and BMI was predictive of NT-proBNP independently from age, LVEF, and eGFR (r=−0.152, p&lt;0.001). The best NT-proBNP cut-offs to predict 5-year cardiac mortality were significantly lower in mildly [1044 ng/L; AUC 0.663 (Sen 66%; Spe 59%), p&lt;0.001] moderately [736 ng/L; AUC 0.670 (Sen 76%; Spe 52%), p&lt;0.001]), and severely [1060 ng/L; AUC 0.635 (Sen 57%; Spe 69%), p=0.021] obese patients compared to nonobese individuals [2034 ng/L; AUC 0.714 (Sens. 65%; Spec. 66%), p&lt;0.001]. Further, NT-proBNP independently predicted 5-year cardiac death in nonobese, mildly and moderately obese patients (all p&lt;0.001), but not in severely obese patients (p=0.457). Similar findings were observed for the secondary endpoint of 5-year all-cause mortality.

Conclusions

Compared to nonobese CHF patients, obese patients have lower circulating NT-proBNP levels, which retain independent prognostic significance for cardiac and all-cause mortality across most categories of obesity. BMI-adjusted NT-proBNP cut-offs might be considered for prognostic stratification in obese patients with CHF.

Funding Acknowledgement

Type of funding source: None

Central and obstructive apneas prevalence in heart failure with reduced, mid-range and preserved ejection fraction

Background

Central apneas (CA) and obstructive apneas (OA) are highly prevalent in heart failure (HF) both with reduced and preserved systolic function. However, a comprehensive evaluation of apnea prevalence across HF according to ejection fraction (i.e HF with patients with reduced, mid-range and preserved ejection fraction- HFrEf, HFmrEF and HFpEF, respectively) throughout the 24 hours has never been done before.

Materials and methods

700 HF patients were prospectively enrolled and then divided according to left ventricular EF (408 HFrEF, 117 HFmrEF, 175 HFpEF). All patients underwent a thorough evaluation including: 2D echocardiography; 24-h Holter-ECG monitoring; cardiopulmonary exercise testing; neuro-hormonal assessment and 24-h cardiorespiratory monitoring.

Results

In the whole population, prevalence of normal breathing (NB), CA and OA at daytime was 40%, 51%, and 9%, respectively, while at nighttime 15%, 55%, and 30%, respectively.

When stratified according to left ventricular EF, CA prevalence decreased from HFrEF to HFmrEF and HFpEF: (daytime CA: 57% vs. 43% vs. 42%, respectively, p=0.001; nighttime CA: 66% vs. 48% vs. 34%, respectively, p&lt;0.0001), while OA prevalence increased (daytime OA: 5% vs. 8% vs. 18%, respectively, p&lt;0.0001; nighttime OA: 20 vs. 29 vs. 53%, respectively, p&lt;0.0001).

When assessing moderte-severe apneas, defined with an apnea/hypopnea index &gt;15 events/hour, prevalence of CA was again higher in HFrEF than HFmrEF and HFpEF both at daytime (daytime moderate-severe CA: 28% vs. 19% and 23%, respectively, p&lt;0.05) and at nighttime (nighttime moderate-severe CA: 50% vs. 39% and 28%, respectively, p&lt;0.05). Conversely, moderate-severe OA decreased from HFrEF to HFmrEF to HFpEF both at daytime (daytime moderate-severe OA: 1% vs. 3% and 8%, respectively, p&lt;0.05) and nighttime (noghttime moderate-severe OA: 10% vs. 11% and 30%, respectively, p&lt;0.05).

Conclusions

Daytime and nighttime apneas, both central and obstructive in nature, are highly prevalent in HF regardless of EF. Across the whole spectrum of HF, CA prevalence increases and OA decreases as left ventricular systolic dysfunction progresses, both during daytime and nighttime.

Funding Acknowledgement

Type of funding source: None

Central apneas and Ticagrelor related dyspnea in patients with acute coronary syndrome

Background

Patients treated with ticagrelor often develop dyspnea of unknown origin. We aim to explore the contribution of central apneas to ticagrelor-related dyspnea in patients with acute coronary syndrome (ACS).

Methods

We consecutively enrolled patients with ACS, preserved left ventricular ejection fraction and no history of obstructive sleep apnea, treated either with ticagrelor 90 mg bid (n=30) or prasugrel 10 mg od (n=24). One week after ACS onset, all patients underwent, beyond thorough cardiovascular and respiratory assessment, 24-hour cardiorespiratory monitoring and assessment of chemosensitivity to hypercapnia.

Results

Patients treated with ticagrelor reported more frequently dyspnea than patients treated with prasugrel (43% versus 4%, p=0.001), despite no difference in demographic, clinical, echocardiographic and pulmonary data. Patients with dyspnea induced by ticagrelor showed higher apnea-hypopnea and central apnea index both at daytime and at nighttime compared to patients treated with ticagrelor but without dyspnea and patients treated with prasugrel (daytime AHI: 26 [7–34] vs 6 [4–14] and 6 [0–11] events/hour; nighttime AHI: 65 [17–72] vs 22 [8–37] and vs 11 [4–23] events/hour; daytime CAI: 5 [1–15] vs 1 [0–6] and 0 [0–1) events/hour; nighttime CAI 34 [2–55] vs 3 [0–9] and 0 [0–1], all p&lt;0.05). Likewise, they also presented with higher hypercapnic ventilatory response (2.4 [1.9–2.7] vs 1.3 [1.1–1.9] and 0.9 [0.5–2.1] L/min/mmHg, all p&lt;0.05).

Conclusions

Central apneas should be considered a likely mechanism of dyspnea in ACS patients treated with ticagrelor. A drug-related sensitization of the chemoreflex may be the cause of ventilatory instability in this setting.

Funding Acknowledgement

Type of funding source: None

Sacubitril/valsartan improves ventilation stability in patients with chronic heart failure

Background

Sacubitril/valsartan (SV) ameliorates symptoms and prognosis in patients with heart failure and reduced ejection fraction (HFrEF), but the reasons for such effects are unclear. The impact of SV on ventilation has never been investigated. In HFrEF, apneas are highly prevalent both at daytime and nighttime and are associated with increased mortality.

Purpose

We hypothesize that treatment with SV could favourably stabilize ventilation by reducing the severity of central apneas in patients with HFrEF.

Methods

51 patients with HFrEF (mean age 67±9 years, mean left ventricular ejection fraction, LVEF 27±7%) and apneas defined by an apnea-hypopnea index, AHI≥5 (median 16, interquartile range 8–28) events/hour, eligible to treatment with SV and previously on optimal medical therapy for HFrEF, were enrolled. An extensive evaluation including cardiac ultrasound and a 24-hour cardiorespiratory monitoring was performed.

Results

After six months of treatment with SV, left ventricle systolic and diastolic function, mitral regurgitation (MR), left atrial volume (LAVI) and systolic pulmonary artery pressure (sPAP) were improved. Severity of apneas was reduced by 50%, 65% and 36% throughout the 24-hour, at daytime and nighttime, respectively.

Conclusion

Besides its known efficacy on cardiac remodeling, SV positively decreases the apneic burden in patients with HFrEF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnostics unrestricted grant

Contrast induced acute kidney injury prevention during angiographic procedure with early renal replacement therapy

Background and purpose

Post-angiography renal replacement therapy (RRT) has shown protective effects from Ci-AKI (contrast induced acute kidney injury) in patients with pre-existing advanced renal disfunction. We analysed a series of 1095 continuative patients who undergone coronary or peripheral angiography in our center. In non-haemodialyzed patients with eGFR &lt;20ml/min/1.73m2 or with poor renal reserve we performed an “early” RRT, starting during angiography procedure and applied for at least 6 h after procedure, thus diverging from previous literature data based only on post-procedure hours delayed RRT application. The RRT modality chosen was CVVHDF (continous veno-venous hemodiafiltration).

Methods

We considered following subjects variability: age, sex, weight, presence of hypertension, dyslipidaemia, diabetes, smoking habitude, left ventricular ejection fraction, amount of contrast media given and shock or infection occurrence during hospital stay. We evaluate statistic significative of serum creatine (SCr) variation in patients receiving RRT from pre-procedure time (T0), at 24h (T1), 48h (T2), 72h (T3) after procedure and at 3–8 weeks follow-up (T4). Quantitative data were compared with Student T test, qualitative data with Chi Square test, considering statistically significant p value &lt;0.05 with two tails. Ci-AKI was defined as serum creatinine rise ≥0.3 mg/dL at 48h from contrast media administration, following KDIGO (kidney disease improving global outcomes) guidelines definition.

Results

26 patients received RRT. Medium SCr at T0 was 3.37 mg/dl and showed a significative reduction (see figure) at T1 (−0.88mg/dl = −20.6%, p=0.003) and T2 (−0.96mg/dl = −18.33%, p=0.029) and a trend towards reduction at T3 (−0.78mg/dl, p=0.174) and at T4 (−0.28mg/dl, p=0.568).

Between 26 pts, 6 pts (23%) developed Ci-AKI. Only contrast media amount significatively diverge between two groups (183 ml in the group with Ci-AKI vs 162 ml in pts with no Ci-AKI, p=0.03), showing also a trend towards significance for infection occurrence (83.3% pts Ci-AKI vs 40% pts no Ci-AKI, p=0.06) and shock onset (33.3%pts Ci-AKI vs 5% pts no Ci-AKI, p=0.06).

Average SCr diverge at T2 (3.18mg/dl Ci-AKI vs 2.04mg/dl no Ci-AKI, p=0.01) and at T3 (3.33mg/dl CI-AKI vs 2.31mg/dl no CI-AKI, p=0.06); we also found a trend towards progressive increase of SCr for Ci-AKI pts (T0-T1: +0.17mg/dl, p=ns; T0-T2: +0.41mg/dl, p=ns; T0-T3: +0.57mg/dl, p=ns; T0-T4: +1.35mg/dl, p=ns) and a significative reduction in SCr for no Ci-AKI pts (T0-T1: −1.23mg/dl = −29.32% p=0.001; T0-T2: −1.46mg/dl = −30.78%, p=0.01; T0-T4: −0.41mg/dl = −15.5%, p=0.05).

Conclusions

Early RRT with CVVHDF modality results effective in 77% of patients in avoiding Ci-AKI, with a significative SCr reduction at 24 and 48h. An increased amount of contrast media is significatively related to Ci-AKI incidence. Ci-AKI development could also possibly be related to shock and infection occurrence.

Figure 1

Funding Acknowledgement

Type of funding source: None

Autoimmune haemolytic anaemia and antiphospholipid antibodies in paediatrics: a systematic review and meta-analysis

INTRODUCTION/OBJECTIVE

The relationship between autoimmune haemolytic anaemia (AIHA) and antiphospholipid antibodies (aPL) has never been addressed via a meta-analysis in the paediatric age group. We evaluated the link between AIHA and aPL in childhood systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS).

METHODS

EMBASE and PubMed were screened from inception to May 2020 and Peto's odds ratio for rare events was employed for the between group comparisons.

RESULTS

The meta-analysis included 11 articles for a total of 575 children: the pooled prevalence of AIHA was greater in (1) IgG aCL-positive than IgG aCL-negative children (39.7% vs 20.9%, p = 0.005); (2) in APS-positive than APS-negative SLE children (36.8% vs 13.2%, p = 0.01); and (3) in SLE-related APS than in primary APS children (53% vs 16.2%, p = 0.008).

CONCLUSIONS

The pooled prevalence of AIHA is greatest in SLE with aPL/APS, low-moderate in SLE without aPL/APS, and lowest in primary APS. Key Points • Antiphospholipid antibodies strongly relate to autoimmune haemolytic anaemia. • Autoimmune haemolytic anaemia is more common in systemic lupus erythematosus with antiphospholipid antibodies.

Cardiogenic shock and acute kidney injury: the rule rather than the exception

Cardiogenic shock (CS) is a life-threatening condition of poor end-organ perfusion, caused by any cardiovascular disease resulting in a severe depression of cardiac output. Despite recent advances in replacement therapies, the outcome of CS is still poor, and its management depends more on empirical decisions rather than on evidence-based strategies. By its side, acute kidney injury (AKI) is a frequent complication of CS, resulting in the onset of a cardiorenal syndrome. The combination of CS with AKI depicts a worse clinical scenario and holds a worse prognosis. Many factors can lead to acute renal impairment in the setting of CS, either for natural disease progression or for iatrogenic causes. This review aims at collecting the current evidence-based acknowledgments in epidemiology, pathophysiology, clinical features, diagnosis, and management of CS with AKI. We also attempted to highlight the major gaps in evidence as well as to point out possible strategies to improve the outcome.

Antiphospholipid antibodies and lower extremity peripheral artery disease: A systematic review and meta-analysis

AIM

To evaluate the clinical relevance of antiphospholipid antibodies (aPL) in patients with lower extremity peripheral artery disease (PAD).

DATA SOURCES

EMBASE and MEDLINE databases were searched from inception to March 2020 for clinical studies reporting on the association between of aPL [IgG/IgM anticardiolipin (aCL) and lupus anticoagulant (LA)] and PAD.

METHODS

We determined the pooled prevalence (PP) of patients positive for aPL in PAD or the PP of PAD in patients positive for aPL; we employed Peto's odds ratio with random effect for the meta-analysis.

RESULTS

Twenty-one studies comprising 6,057 patients were evaluated: in patients with PAD, the PP of IgG aCL was 12% vs 4.1% in those without, IgM aCL was 13.2% vs 2.1%, and LA 13.3% vs 3.3%, respectively. The PP of patients with LA was greater in critical limb ischemia than in the control group (19.3% vs 4.2%). Also, the PP of patients with LA was greater in the failed than in the successful revascularisation group (35.8% vs 15.8%). The PP of post-procedural revascularisation failures was similar in the groups given or not given oral anticoagulation (59.2% vs 61.9%).

CONCLUSION

All the aPL related to PAD regardless of diagnostic definition used, whereas LA related also to critical limb ischaemia and failed revascularisation. Data expressed as percentage of participants positive for aPL limit the interpretation of these relationships.

Antiphospholipid antibodies in end-stage renal disease: A systematic review and meta-analysis

INTRODUCTION

The relationship between autoimmune hemolytic anemia and antiphospholipid antibodies (aPL) and/or antiphospholipid syndrome has never been systematically addressed.

METHODS

Systematic review of EMBASE and PubMed databases performed according to PRISMA guidelines from inception to March 2020; meta-analysis performed by Peto's odds ratio for rare events.

FINDINGS

Forty-five studies with different outcomes met the inclusion/exclusion criteria. The pooled prevalence (PP) of IgG anticardiolipin antibodies (aCL) positivity was greater in end-stage renal disease (ESRD) than controls (20.2% vs. 2.6%, P = 0.001, I²  >80%; I² = heterogeneity), particularly in hemodialysis patients (18.3% vs. 8%, I² = 0%). The PP of lupus anticoagulant was greater in ESRD than controls (8.7% vs. 0.2%, P < 0.0001, I² = 0%). The standardized mean difference of IgG aCL favored ESRD rather than controls (P < 0.0001, I² =97%). The PP of fistula occlusion was greater in IgG aCL-positive patients than negative patients (39% vs. 27%, I² =97%); the PP of IgG aCL positivity was greater in patients with fistula occlusion than without fistula occlusion (26.9% vs. 23.2%, P = 0.01, I² =72%); the same applied to the PP of lupus anticoagulant positivity (23% vs. 0.3%, P < 0.0001, I² = 0%). The standardized mean difference of IgG aCL favored fistula occlusion (P = 0.004, I² = 91%).

DISCUSSION

Lupus anticoagulant relates to ESRD regardless of management whereas IgG aCL relates specifically to ESRD on hemodialysis, but only lupus anticoagulant associates with fistula occlusion. The expression of aPL as patients positive for aPL rather than as titers precludes further assumptions on the relationship.

A nanomechanical model enables comprehensive characterization of biological tissues in ultrasound imaging

Sonography, elastography, sonoelastography are ultrasound imaging techniques commonly used in the clinical practice for the diagnosis of many pathological conditions. These highly reliable, non-invasive methods use high frequency, elastic pressure waves (ultrasounds) to interrogate the internal structure of biological tissues and organs, and the continuum mechanics hypothesis to reconstruct, from the output of the system, the biophysical characteristics of the samples. Nevertheless, continuum mechanics disregards the discrete nature of tissues and organs, resulting in an inability for the model to describe some important tissue biophysical characteristics such as the cell size and their spatial layout. Here, we used the theory of doublet mechanics - a discrete nano-mechanical field theory - to model the propagation of ultrasounds in a multilayered biological tissue. We found that the output of the model exhibits a very high sensitivity to the macro and micro characteristics of the tissue, including cell size. We used results from the model to correlate the internal structure of the samples to the reflection coefficient, i.e. the continuum level response of the system. This model, and its more sophisticated evolutions that will be developed over time, can complement traditional ultrasound imaging, and provide ways to analyze non-invasively living tissues with a resolution inaccessible to conventional techniques of analysis, including positron emission tomography, computer tomography, and magnetic resonance.

Validity of Coagulation Activation Markers in Antiphospholipid Syndrome: A Systematic Review and Meta-analysis with a Short Data Report

Prothrombin fragment F1 + 2 (F1 + 2) and thrombin–antithrombin (TAT) have been assessed in antiphospholipid syndrome (APS) but without evaluating a direct relationship with antiphospholipid (aPL) antibody titers. This article aims to investigate a direct relationship between aPL and F1 + 2 and perform a systematic review and meta-analysis of F1 + 2 and TAT in APS. Systematic search was performed using EMBASE and PubMed databases from January 1982 to December 2018 and random effects meta-analyses for continuous outcomes. This is a cross-sectional case–control study; immunoglobulin G/immunoglobulin M (IgG/IgM) anticardiolipin (aCL) anti-β2-glycoprotein-I, antiprothrombin (aPT) antibodies, F1 + 2, and lupus anticoagulants (LA) were measured in 25 thrombotic primary APS (PAPS), 9 nonthrombotic carriers of aPL, and 18 controls. The significant effect size (ES) for F1 + 2 between aPL +ve and aPL −ve systemic lupus erythematosus (SLE) and between aPL +ve SLE and control displayed high heterogeneity. The significant ES for F1 + 2 between aPL −ve SLE and controls displayed no heterogeneity. The ES for TAT between aPL +ve and aPL −ve SLE patients and between aPL −ve SLE and controls was low, without heterogeneity. Mean F1 + 2 was greater in PAPS (p < 0.0001), inversely correlated with IgG aCL, IgM aPT, and LA (p = 0.001, 0.03, and 0.01, respectively), though only IgG aCL negatively predicted F1 + 2 (p = 0.01). IgG aCL inversely predicts F1 + 2. IgG aCL positivity introduces heterogeneity in the F1 + 2 ES, whereas the lack of heterogeneity in the ES for TAT may indicate poor TAT formation in aPL +ve group. Thus, F1 + 2 measurements may be unfounded as already demonstrated for TAT in the 1990s.

Cortical-like mini-columns of neuronal cells on zinc oxide nanowire surfaces

A long-standing goal of neuroscience is a theory that explains the formation of the minicolumns in the cerebral cortex. Minicolumns are the elementary computational units of the mature neocortex. Here, we use zinc oxide nanowires with controlled topography as substrates for neural-cell growth. We observe that neuronal cells form networks where the networks characteristics exhibit a high sensitivity to the topography of the nanowires. For certain values of nanowires density and fractal dimension, neuronal networks express small world attributes, with enhanced information flows. We observe that neurons in these networks congregate in superclusters of approximately 200 neurons. We demonstrate that this number is not coincidental: the maximum number of cells in a supercluster is limited by the competition between the binding energy between cells, adhesion to the substrate, and the kinetic energy of the system. Since cortical minicolumns have similar size, similar anatomical and topological characteristics of neuronal superclusters on nanowires surfaces, we conjecture that the formation of cortical minicolumns is likewise guided by the interplay between energy minimization, information optimization and topology. For the first time, we provide a clear account of the mechanisms of formation of the minicolumns in the brain.

Relating the rate of growth of metal nanoparticles to cluster size distribution in electroless deposition

Electroless deposition on patterned silicon substrates enables the formation of metal nanomaterials with tight control over their size and shape. In the technique, metal ions are transported by diffusion from a solution to the active sites of an autocatalytic substrate where they are reduced as metals upon contact. Here, using diffusion limited aggregation models and numerical simulations, we derived relationships that correlate the cluster size distribution to the total mass of deposited particles. We found that the ratio ξ between the rates of growth of two different metals depends on the ratio γ between the rates of growth of clusters formed by those metals through the linearity law ξ = 14(γ - 1). We then validated the model using experiments. Different from other methods, the model derives k using as input the geometry of metal nanoparticle clusters, decoded by SEM or AFM images of samples, and a known reference.

Modelling soil erosion in a Mediterranean watershed: Comparison between SWAT and AnnAGNPS models

In this study, the simulations generated by two of the most widely used hydrological basin-scale models, the Annualized Agricultural Non-Point Source (AnnAGNPS) and the Soil and Water Assessment Tool (SWAT), were compared in a Mediterranean watershed, the Carapelle (Apulia, Southern Italy). Input data requirements, time and efforts needed for input preparation, strength and weakness points of each model, ease of use and limitations were evaluated in order to give information to users. Models were calibrated and validated at monthly time scale for hydrology and sediment load using a four year period of observations (streamflow and suspended sediment concentrations). In the driest year, the specific sediment load measured at the outlet was 0.89 t ha^-1 yr^-1, while the simulated values were 0.83 t ha^-1 yr^-1 and 1.99 t ha^-1 yr^-1 for SWAT and AnnAGNPS, respectively. In the wettest year, the specific measured sediment load was 7.45 t ha^-1 yr^-1, and the simulated values were 8.27 t ha^-1 yr^-1 and 6.23 t ha^-1 yr^-1 for SWAT and AnnAGNPS, respectively. Both models showed from fair to a very good correlation between observed and simulated streamflow and satisfactory for sediment load. Results showed that most of the basin is under moderate (1.4-10 t ha^-1 yr^-1) and high-risk erosion (> 10 t ha^-1 yr^-1). The sediment yield predicted by the SWAT and AnnAGNPS models were compared with estimates of soil erosion simulated by models for Europe (PESERA and RUSLE2015). The average gross erosion estimated by the RUSLE2015 model (12.5 t ha^-1 yr^-1) resulted comparable with the average specific sediment yield estimated by SWAT (8.8 t ha^-1 yr^-1) and AnnAGNPS (5.6 t ha^-1 yr^-1), while it was found that the average soil erosion estimated by PESERA is lower than the other estimates (1.2 t ha^-1 yr^-1).

Oxidative/nitrative stress in the pathogenesis of systemic sclerosis: are antioxidants beneficial?

Systemic sclerosis (SSc) is a multisystem autoimmune disease: characterised from the clinical side by progressive vasculopathy and fibrosis of the skin and different organs and from the biochemical side by fibroblast deregulation with excessive production of collagen and increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). The latter contributes to an overproduction of reactive oxygen species that through an autocrine loop maintains NOX4 in a state of activation. Reactive oxygen and nitrogen species are implicated in the origin and perpetuation of several clinical manifestations of SSc having vascular damage in common; attempts to dampen oxidative and nitrative stress through different agents with antioxidant properties have not translated into a sustained clinical benefit. Objective of this narrative review is to describe the origin and clinical implications of oxidative and nitrative stress in SSc, with particular focus on the central role of NOX4 and its interactions, to re-evaluate the antioxidant approaches so far used to limit disease progression, to appraise the complexity of antioxidant treatment and to touch on novel pathways elements of which may represent specific treatment targets in the not so distant future.

Silica diatom shells tailored with Au nanoparticles enable sensitive analysis of molecules for biological, safety and environment applications

Diatom shells are a natural, theoretically unlimited material composed of silicon dioxide, with regular patterns of pores penetrating through their surface. For their characteristics, diatom shells show promise to be used as low cost, highly efficient drug carriers, sensor devices or other micro-devices. Here, we demonstrate diatom shells functionalized with gold nanoparticles for the harvesting and detection of biological analytes (bovine serum albumin-BSA) and chemical pollutants (mineral oil) in low abundance ranges, for applications in bioengineering, medicine, safety, and pollution monitoring.

The effect of connectivity on information in neural networks

We present a mathematical model that quantifies the amount of information exchanged in bi-dimensional networks of nerve cells as a function of network connectivity Q. Upon varying Q over a significant range, we found that, from a certain cell density onwards, 90% of the maximal information transferred I(Q) in a random neuronal network is already reached with just 40% of the total possible connections Q among the cells. As a consequence, the system would not benefit from additional connections in terms of the amount of I(Q), in agreement with the tendency of brains to minimize Q because of its energetic costs. The model may reveal the circuits responsible for neurodegenerative disorders in that neurodegeneration can be regarded as a connective failure affecting information.