Cobalt-based nanoparticles synthesis in organic solvents with environmentally sound processes

A process for the synthesis of cobalt-based nanoparticles is proposed, where standard reducing agent like hydrazine, alkali metal borohydrides, hypophosphites or other toxic reducing agents have not been employed. The solvothermal reaction is carried out in organic solvents and the dimension of the nanoparticles thus obtained have been analyzed by dynamic light scattering. Cobalt nitrate proved to be an efficient precursor, in agreement with previous literature works where its suitability for analogous processes has been tested and compared with the efficiency typical of other precursors routinely used. The soundness of this method, in terms of process safety, has been checked by analyzing the formation of toxic by-products that could be formed by side-reactions between the precursor and the solvent. This work may add some more details to a discussion pertaining to the accidental formation of N-nitroso derivatives of aliphatic compounds in the presence of alkanolamines and oxides of nitrogen

Reconciliation of flow rate measurements in the presence of solid particles

The reconciliation of flow rates of fluids entraining and reacting with solid particles is considered in this article. It is shown that, in case the amount of solid particles is not high, the reconciliation problem can be addressed formally as a rectification that includes additional components and solved using the techniques proposed by earlier research [Crowe, C. M., Garcia Campos, Y. A, Hrymak, A. AIChE J. 1983, 29, 881-888]. Furthermore, it is shown that the introduction of the interaction law between the fluid and the solid phase can improve the overall reliability of the reconciliation procedure

Polarization effects in modelling unsteady-state reverse osmosis

Desalination and ultrafiltration processes have gained a growing interest in recent years and a very rich literature has been developed to model both large scale plants and local convectiondiffusion phenomena governing the single-step units [1-2]. In the latter context, membrane separation technologies by reverse osmosis are a very promising tool to realize separation of ions from aqueous solutions and in recovery of valuable or toxic cations from wastewaters. The most important modelling techniques in describing reverse osmosis rely upon different schemes that, as a first approximation, can be summarized in semi-emipirical mass-transfer models, film theory and more accurate differential-algebraic models accounting for hydrodynamics and interface thermodynamics [3]. Semi-empirical models represent a first and maybe rough attempt where the concentration profile is studied by analogies with heat transfer correlations. Film theory can be considered a satisfactory trade-off between computational simplicity and reliability of results. In fact, this theory allows to treat a complex mass transfer process as a simple one-dimensional problem provided the axial convection close to the membrane surface is assumed negligible. However, the most interesting approach to better foresee the concentration trend near the membrane surface is based on an unsteady-state modelling of the diffusion-convection equation in one or two space variables [4-5]. According to this strategy, a progressive deterioration in separation yield owing to both polarization effects and membrane fouling can be predicted with good accuracy. Unfortunately, this technique is often affected by numerical instabilities related, for instance, to a bad matching between initial and boundary conditions that may severely endanger the applicability of the method. In this paper, we propose a numerical simulation of a single-step separation in a spiral wound module in unsteadystate regime with axial and radial diffusion. The scheme is organized as follows. In section 2, we outline the essentials of the model and we describe the numerical algorithm. In section 3, we present the results of the simulations obtained with different values of the parameters conditioning the yield of the global process. In particular, we estimate the role of the diffusivity in tuning the onset of the polarization regime. In section 3 we draw the conclusion and trace the direction for future works

Clinical Features of Patients With Cervical Artery Dissection and Fibromuscular Dysplasia

BACKGROUND AND PURPOSE: Observational studies have suggested a link between fibromuscular dysplasia and spontaneous cervical artery dissection (sCeAD). However, whether patients with coexistence of the two conditions have distinctive clinical characteristics has not been extensively investigated.METHODS: In a cohort of consecutive patients with first-ever sCeAD, enrolled in the setting of the multicenter IPSYS CeAD study (Italian Project on Stroke in Young Adults Cervical Artery Dissection) between January 2000 and June 2019, we compared demographic and clinical characteristics, risk factor profile, vascular pathology, and midterm outcome of patients with coexistent cerebrovascular fibromuscular dysplasia (cFMD; cFMD+) with those of patients without cFMD (cFMD-).RESULTS: A total of 1283 sCeAD patients (mean age, 47.8±11.4 years; women, 545 [42.5%]) qualified for the analysis, of whom 103 (8.0%) were diagnosed with cFMD+. In multivariable analysis, history of migraine (odds ratio, 1.78 [95% CI, 1.13-2.79]), the presence of intracranial aneurysms (odds ratio, 8.71 [95% CI, 4.06-18.68]), and the occurrence of minor traumas before the event (odds ratio, 0.48 [95% CI, 0.26-0.89]) were associated with cFMD. After a median follow-up of 34.0 months (25th to 75th percentile, 60.0), 39 (3.3%) patients had recurrent sCeAD events. cFMD+ and history of migraine predicted independently the risk of recurrent sCeAD (hazard ratio, 3.40 [95% CI, 1.58-7.31] and 2.07 [95% CI, 1.06-4.03], respectively) in multivariable Cox proportional hazards analysis.CONCLUSIONS: Risk factor profile of sCeAD patients with cFMD differs from that of patients without cFMD. cFMD and migraine are independent predictors of midterm risk of sCeAD recurrence

Long-term outcome of cervical artery dissection IPSYS CeAD: study protocol, rationale, and baseline data of an Italian multicenter research collaboration

Long-term consequences of cervical artery dissection (CeAD), a major cause of ischemic stroke in young people, have been poorly investigated. The Italian Project on Stroke at Young Age – Cervical Artery Dissection (IPSYS CeAD) project is a multicenter, hospital-based, consecutively recruiting, observational, cohort study aimed to address clinically important questions about long-term outcome of CeAD patients, which are not covered by other large-scale registries. Patients with radiologically diagnosed CeAD were consecutively included in the registry. Baseline demographic and clinical variables, as well as information on risk factors, were systematically collected for each eligible patient. Follow-up evaluations were conducted between 3 and 6 months after the initial event (t1) and then annually (t2 at 1 year, t3 at 2 years , and so on), in order to assess outcome events (long-term recurrent CeAD, any fatal/ nonfatal ischemic stroke, transient ischemic attack (TIA), or other arterial thrombotic event, and death from any cause). Between 2000 and 2019, data from 1530 patients (age at diagnosis, 47.2 ± 11.5 years; women, 660 [43.1%]) have been collected at 39 Italian neurological centers. Dissection involved a single vessel in 1308 (85.5%) cases and caused brain ischemia in 1303 (85.1%) (190 TIA/1113 ischemic stroke). Longitudinal data are available for 1414 (92.4%) patients (median follow-up time in patients who did not experience recurrent events, 36.0 months [25th to 75th percentile, 63.0]). The collaborative IPSYS CeAD effort will provide novel information on the long-term outcome of CeAD patients. This could allow for tailored treatment approaches based on patients’ individual characteristics. © 2020, Fondazione Società Italiana di Neurologia

Association between migraine and cervical artery dissection the Italian project on stroke in young adults

IMPORTANCE Although sparse observational studies have suggested a link between migraine and cervical artery dissection (CEAD), any association between the 2 disorders is still unconfirmed. This lack of a definitive conclusion might have implications in understanding the pathogenesis of both conditions and the complex relationship between migraine and ischemic stroke (IS). OBJECTIVE To investigate whether a history of migraine and its subtypes is associated with the occurrence of CEAD. DESIGN, SETTING, AND PARTICIPANTS A prospective cohort study of consecutive patients aged 18 to 45 years with first-ever acute ischemic stroke enrolled in the multicenter Italian Project on Stroke in Young Adults was conducted between January 1, 2000, and June 30, 2015. In a case-control design, the study assessed whether the frequency of migraine and its subtypes (presence or absence of an aura) differs between patients whose IS was due to CEAD (CEAD IS) and those whose IS was due to a cause other than CEAD (non-CEAD IS) and compared the characteristics of patients with CEAD IS with and without migraine. MAIN OUTCOMES AND MEASURES Frequency of migraine and its subtypes in patients with CEAD IS vs non-CEAD IS. RESULTS Of the 2485 patients (mean [SD] age, 36.8 [7.1] years; women, 1163 [46.8%]) included in the registry, 334 (13.4%) had CEAD IS and 2151 (86.6%) had non-CEAD IS. Migraine was more common in the CEAD IS group (103 [30.8%] vs 525 [24.4%], P = .01), and the difference was mainly due to migraine without aura (80 [24.0%] vs 335 [15.6%], P < .001). Compared with migraine with aura, migraine without aura was independently associated with CEAD IS (OR, 1.74; 95%CI, 1.30-2.33). The strength of this association was higher in men (OR, 1.99; 95%CI, 1.31-3.04) and in patients 39.0 years or younger (OR, 1.82; 95%CI, 1.22-2.71). The risk factor profile was similar in migrainous and non-migrainous patients with CEAD IS (eg, hypertension, 20 [19.4%] vs 57 [24.7%], P = .29; diabetes, 1 [1.0%] vs 3 [1.3%], P > .99). CONCLUSIONS AND RELEVANCE In patients with IS aged 18 to 45 years, migraine, especially migraine without aura, is consistently associated with CEAD. This finding suggests common features and warrants further analyses to elucidate the underlying biologic mechanisms

Mapping the human genetic architecture of COVID-19

The genetic make-up of an individual contributes to the susceptibility and response to viral infection. Although environmental, clinical and social factors have a role in the chance of exposure to SARS-CoV-2 and the severity of COVID-191,2, host genetics may also be important. Identifying host-specific genetic factors may reveal biological mechanisms of therapeutic relevance and clarify causal relationships of modifiable environmental risk factors for SARS-CoV-2 infection and outcomes. We formed a global network of researchers to investigate the role of human genetics in SARS-CoV-2 infection and COVID-19 severity. Here we describe the results of three genome-wide association meta-analyses that consist of up to 49,562 patients with COVID-19 from 46 studies across 19 countries. We report 13 genome-wide significant loci that are associated with SARS-CoV-2 infection or severe manifestations of COVID-19. Several of these loci correspond to previously documented associations to lung or autoimmune and inflammatory diseases3–7. They also represent potentially actionable mechanisms in response to infection. Mendelian randomization analyses support a causal role for smoking and body-mass index for severe COVID-19 although not for type II diabetes. The identification of novel host genetic factors associated with COVID-19 was made possible by the community of human genetics researchers coming together to prioritize the sharing of data, results, resources and analytical frameworks. This working model of international collaboration underscores what is possible for future genetic discoveries in emerging pandemics, or indeed for any complex human disease