Intermolecular interactions of substituted benzenes on multi-walled carbon nanotubes grafted on HPLC silica microspheres and interaction study through artificial neural networks

Purified multi-walled carbon nanotubes (MWCNTs) grafted onto silica microspheres by gamma-radiation were applied as a HPLC stationary phase for investigating the intermolecular interactions between MWCNTs and substituted benzenes. The synthetic route, simple and not requiring CNTs derivatization, involved no alteration of the nanotube original morphology and physical–chemical properties. The affinity of a set of substituted benzenes for the MWCNTs was studied by correlating the capacity factor (k′) of each probe to its physico-chemical characteristics (calculated by Density Functional Theory). The correlation was found through a theoretical approach based on feedforward neural networks. This strategy was adopted because today these calculations are easily affordable for small molecules (like the analytes), and many critical parameters needed are not known. This might increase the applicability of the proposed method to other cases of study. Moreover, it was seen that the normal linear fit does not provide a good model. The interaction on the MWCNT phase was compared to that of an octadecyl (C18) reversed phase, under the same elution conditions. Results from trained neural networks indicated that the main role in the interactions between the analytes and the stationary phases is due to dipole moment, polarizability and LUMO energy. As expected for the C18 stationary phase correlation, is due to dipole moment and polarizability, while for the MWCNT stationary phase primarily to LUMO energy followed by polarizability, evidence for a specific interaction between MWCNTs and analytes. The CNT-based hybrid material proved to be not only a chromatographic phase but also a useful tool to investigate the MWCNT-molecular interactions with variously substituted benzenes. Keywords: Carbon nanotubes, Feedforward neural networks, Intermolecular interaction, Liquid chromatograph

CO2 and CH4 fluxes across a Nuphar lutea (L.) Sm. stand

Floating-leaved rhizophytes can significantly alter net carbon dioxide (CO 2) and methane (CH 4) exchanges with the atmosphere in freshwater shallow environments. In particular, CH 4 efflux can be enhanced by the aerenchyma-mediated mass flow, while CO 2 release from supersaturated waters can be reversed by the plant uptake. Additionally, the floating leaves bed can hamper light penetration and oxygen (O 2) diffusion from the atmosphere, thus altering the dissolved gas dynamics in the water column. In this study, net fluxes of CO 2 and CH 4 were measured seasonally across vegetated [Nuphar lutea (L.) Sm.] and free water surfaces in the Busatello wetland (Northern Italy). Concomitantly, dissolved gas concentrations were monitored in the water column and N. lutea leaf production was estimated by means of biomass harvesting. During the vegetative period (May-August), the yellow waterlily stand resulted a net sink for atmospheric carbon (from 97.5 to 110.6 g C-CO 2 m -2), while the free water surface was a net carbon source (166.3 g C-CO 2 m -2). Both vegetated and plant-free areas acted as CH 4 sources, with an overall carbon release comprised between 71.6 and 113.3 g C-CH 4 m -2. On the whole, water column chemistry was not affected by the presence of the floating leaves; moreover, no significant differences in CH4 efflux were evidenced between the vegetated and plant-free areas. In general, this study indicates that the colonization of shallow aquatic ecosystems by N. lutea might not have the same drastic effect reported for free-floating macrophytes

Ontology-driven Generation of Training Paths in the Legal Domain

This paper presents a methodology for helping citizens obtain guidance and training when submitting a natural language description of a legal case they are interested in. This is done via an automatic mechanism, which firstly extracts relevant legal concepts from the given textual description, by relying upon an underlying legal ontology built for such a purpose and an enrichment process based on common-sense knowledge. Then, it proceeds to generate a training path meant to provide citizens with a better understanding of the legal issues arising from the given case, with corresponding links to relevant laws and jurisprudence retrieved from an external legal repository. This work de-scribes the creation of the underlying legal ontology from existing sources and the ontology integration algorithm used for its production; besides, it details the generation of the training paths and reports the results of the preliminary experimentation that has been carried out so far. This methodology has been implemented in an Online Dispute Resolution (ODR) system that is part of an Italian initiative for assisted legal mediation

COVID-19 in rheumatic diseases in Italy: first results from the Italian registry of the Italian Society for Rheumatology (CONTROL-19)

OBJECTIVES: Italy was one of the first countries significantly affected by the coronavirus disease 2019 (COVID-19) epidemic. The Italian Society for Rheumatology promptly launched a retrospective and anonymised data collection to monitor COVID-19 in patients with rheumatic and musculoskeletal diseases (RMDs), the CONTROL-19 surveillance database, which is part of the COVID-19 Global Rheumatology Alliance. METHODS: CONTROL-19 includes patients with RMDs and proven severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) updated until May 3rd 2020. In this analysis, only molecular diagnoses were included. The data collection covered demographic data, medical history (general and RMD-related), treatments and COVID-19 related features, treatments, and outcome. In this paper, we report the first descriptive data from the CONTROL-19 registry. RESULTS: The population of the first 232 patients (36% males) consisted mainly of elderly patients (mean age 62.2 years), who used corticosteroids (51.7%), and suffered from multi-morbidity (median comorbidities 2). Rheumatoid arthritis was the most frequent disease (34.1%), followed by spondyloarthritis (26.3%), connective tissue disease (21.1%) and vasculitis (11.2%). Most cases had an active disease (69.4%). Clinical presentation of COVID-19 was typical, with systemic symptoms (fever and asthenia) and respiratory symptoms. The overall outcome was severe, with high frequencies of hospitalisation (69.8%), respiratory support oxygen (55.7%), non-invasive ventilation (20.9%) or mechanical ventilation (7.5%), and 19% of deaths. Male patients typically manifested a worse prognosis. Immunomodulatory treatments were not significantly associated with an increased risk of intensive care unit admission/mechanical ventilation/death. CONCLUSIONS: Although the report mainly includes the most severe cases, its temporal and spatial trend supports the validity of the national surveillance system. More complete data are being acquired in order to both test the hypothesis that RMD patients may have a different outcome from that of the general population and determine the safety of immunomodulatory treatments

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Influence of Potamogeton pectinatus and microphytobenthos on benthic metabolism in a freshwater littoral sediment in an agricultural landscape: N assimilation vs N removal

The influence of Potamogeton pectinatus colonization on benthic nitrogen dynamics was quantified in the littoral zone of a lowland pit lake with high nitrate availability (~200 µM). Our hypothesis was that in aquatic environments where nitrogen availability is not limiting, colonization by rooted macrophytes changes the dynamics of the benthic nitrogen cycle, stimulating N assimilation and denitrification, and increasing the system capacity to mitigate external nitrogen loads. To test this hypothesis we quantified and compared light and dark seasonal variations of benthic metabolism, dissolved inorganic nitrogen fluxes, denitrification and N assimilation rates in an area colonized by P. pectinatus and a reference site colonized by microphytobenthos. In both areas the benthic system was net autotrophic and a sink for dissolved inorganic nitrogen (2241-2644 mmol m-2 y-1). Plant colonization increased nitrogen losses via denitrification by 30% compared to the unvegetated area. In contrast to what is generally observed in coastal marine systems, where the presence of rooted macrophytes limits denitrification rates, under the very high nitrate concentrations in the studied lake, both denitrification (1237-1570 mmol m-2 y-1) and N-assimilation (1039-1095 mmol m-2 y-1) played important and comparable roles in the removal of dissolved inorganic nitrogen from the water column

Decomposition of four macrophytes in wetland sediments: organic matter and nutrient decay and associated benthic processes.

Decomposition rates of Phragmites australis, Carex riparia, Nuphar luteum and Salvinia natans and benthic processes were measured from December 2003 to December 2004 in a shallow wetland (Paludi di Ostiglia, Northern Italy) by means of litter bags and intact cores incubations. Decay rate was highest for N. luteum (k = 0.0152 d-1), intermediate for S. natans (k = 0.0041 d-1) and similar for P. australis (k = 0.0027 d-1) and C. riparia (k = 0.0028 d-1). Benthic metabolism followed a seasonal pattern with summer peaks of O2 demand and TCO2, CH4 and NH4+ efflux whilst soluble reactive phosphorus (SRP) fluxes were negligible also under hypoxic conditions, indicating that P was mainly retained by sediment. The initial C:P ratio was similar in N. luteum and S. natans (∼170) and significantly lower than that of P. australis and C. riparia (∼360). During the detritus decay P was progressively lost by N. luteum and S. natans tissues, whereas, after an initial leaching, it was probably re-used during the microbial decomposition of the more refractory P. australis and C. riparia detritus. Nuphar luteum, P. australis and S. natans had comparable initial C:N mass ratio (∼15), significantly lower than that of C. riparia (∼26). The C:N ratio was rather constant for N. luteum (12.9 ± 1.5) and S. natans (14.6 ± 0.9), decreased slightly to below 20 for C. riparia and increased up to 30 for P. australis. Overall, differences among species were likely due to the recalcitrance of decomposing detritus, whilst process rates were controlled by limitation of microbial processes by nutrients and electron acceptor availabilit

Do oxic–anoxic transitions constrain organic matter mineralization in eutrophic freshwater wetlands?

This study aims at investigating decomposition processes in wetlands that are daily or seasonally exposed to intermittent oxic and anoxic conditions. We hypothesized that in wetland ecosystems where anoxia regularly establishes, decomposition rates are not affected by oxygen shortage, especially when nitrates are available. Monitoring and experiments were performed from December 2003 to January 2005 in one of the widest (81 ha) freshwater wetlands in the Po river floodplain (Natural Reserve Paludi del Busatello, Italy). Intact sediment cores were sampled on a seasonal basis. Sediment–water fluxes of oxygen, dissolved inorganic carbon, methane, and inorganic nitrogen were determined under oxic and anoxic conditions. Oxic–anoxic transitions always resulted in enhanced ammonium, dissolved inorganic carbon, and methane effluxes. At high temperatures, the methane release from sediments was inversely related to both nitrate concentrations and uptake. Likely, nitrate can compensate for the oxygen deficiency while maintaining an oxidative metabolism, either supporting microbial decomposition as an electron acceptor or stimulating the oxidation of the byproducts of the anaerobic metabolism, e.g., methane. This is a key point as the number of temperate wetlands with concurrent nitrate pollution and oxygen shortage is increasing throughout the world