A new approach in the use of SIT in determining the dependence on ionic strength of activity coefficients. Application to some chloride salts of interest in the speciation of natural fluids

AbstractThis paper describes a modified version of the SIT (Specific ion Interaction Theory) method and its use in determining the dependence on ionic strength of activity coefficients. In the new approach the interaction coefficients (e) are not constant but depend on ionic strength (I /mol kg-1) according to the simple relationship:e = e∞+ (e0 - e∞) / (l + 1)where e0 and are true constants for I→ 0 and l→ ∞, respectively. To check the two parameter SIT equation, we calculated e0 and for the activity coefficients of HCl, LiCl, NaCl, KCl, MgCl2, CaCl2 and SrCl2, in a wide ionic strength range (0.1 ≤ l/mol kg-1 ≤ 4.5, for KCl; 0.1 ≤ l/mol kg-1 ≤ 6, for HCl, LiCl, NaCl; 0.3 ≤ l/mol kg-1 ≤ 12, for SrCl2; 0.3 ≤ l/mol kg-1 ≤ 15, for MgCl2; 0.3 ≤ l/mol kg-1 ≤ 18, for CaCl2). Results show that the γ values calculated using this approach fit quite well over the whole I-range for all the electrolytes considered. Comparison is made with the analogous one parameter SIT equation. The temperature coefficients of inter..

A NEW INDOOR LIDAR-BASED MMS CHALLENGING COMPLEX ARCHITECTURAL ENVIRONMENTS

Abstract. The use of moving devices equipped with range- and image-based sensor, generically defined Mobile Mapping systems (MMS), have been quite a disruptive innovation in the development of Geomatics techniques for 3D surveying large indoor-outdoor spaces and offer multiple solutions. The recent expansion of portable devices in the form of trolleys, backpacks, handheld tools largely implements SLAM (Simultaneous Localization and Mapping) algorithms and technology based on both Lidar and/or visual solutions for answering to the positioning and the 3D reconstruction problems. The research on MMS is directed to improve both multi-sensor integration implementation and usability of systems in diversified use contexts and application fields. The aim of the presented research is the evaluation of the potential of the Swift system recently developed by FARO Technologies, that has been fine-tuned for regular and large extent interiors mapping (such as factories, hospitals, airports, offices). The work tries to preliminary investigate the data delivery and usability of the integrated system. This is based on three elements mounted on a sliding trolley moved by the operator walking: the ScanPlan profilometer working for the 2D SLAM mapping, the static TLS Focus S-series, and the smartphone managing the sensors operation and the acquisition progress. The evaluation strategy undertaken will be based on the global and local performance analysis related to the trajectory, the data accuracy, the metric content and consistency. Two test studies belonging to the 20th century. architecture are presented in a preliminary framework of evaluation and validation: a Liberty-style cinema and the Torino Esposizioni Hall B designed in ferrocement by pier Luigi Nervi

Documenting Complexity for the 20TH Century Heritage: the Enriched 3d Models of the Turin Exposition Nervi's Halls Digitization

Abstract. Great attention is increasingly paid to the heritage belonging to the XX century, particularly for the spatial structures made of concrete, that are a significant trait of this modern movement architecture. Since they demand today urgent conservation plans sustaining their deterioration, the multidisciplinary researches should devotes a profound investigations for tailored approaches providing a clear indication of best practices and recommendation for correct 3D documentation, information management and structural assessment and monitoring. In this framework, the Geomatics approaches are advancing the interests toward the multi-scale and multi-sensor digitization and for supporting management of complex information in enriched 3D models. The iconic halls B and C in Torino Esposizioni (Italy), designed by Pier Luigi Nervi, is the case study presented. It was recently awarded by the Getty Keeping it Modern grant. The multi-disciplinary research conducted, still in progress, focuses a particularly into the investigation of the structural analysis and consistency of ferrocement elements of the vaulted system finalized to the structural condition assessment. Here the role of multi-scale and multi-sensor 3D models is investigated, such as the development of a digital twin of the halls as a starting point to create an enriched informative system. The reconstruction of this model particularly considering the large extension and the complexity of the spaces, is addressed to works as a collector of 3D multi-sensor data and information related to the diagnostic investigation on structural health monitoring for the durability of ferrocement elements

Chemical speciation of organic matter in natural waters. Interaction of nucleotide 5' mono-, di- and triphosphates with major components of seawater

AbstractThe interactions of nucleotide 5' mono-, di- and triphosphates in a multicomponent ionic medium simulating the macro-composition of seawater (Na+, K+, Ca2+, Mg2+, Cl-, SO42-, Synthetic Sea Water, SSW) have been investigated at different ionic strengths and at T= 25°C. A chemical speciation model, according to which all the internal interactions between the components of the ionic medium are taken into account, was applied to determine the effective formation constants of species in the nucleotide-seawater system. The results were compared to protonation parameters calculated from single electrolyte systems. A simpler model (SSW considered as a single salt BA, with Bz+ and Az-), representative of the cation (Na+, K+, Ca2+, Mg2+) and anion (Cl-, SO42-) macro-components of seawater respectively, was also used to calculate the overall complexing ability of the seawater salt towards all the systems here investigated

Enhancement of Hydrolysis through the Formation of Mixed Heterometal Species: Al3+/CH3Sn3+ Mixtures

ABSTRACT: The hydrolysis of mixed-metal cations (Al3+/CH3Sn3+) was studied in aqueous solutions of NaNO3, at I = 1.00 ± 0.05 mol·dm−3 and T = 298.15 K, by potentiometric technique. Several hydrolytic mixed species are formed in this mixed system, namely, Alp(CH3Sn)q(OH)r with (p, q, r) = (1, 1, 4), (1, 1, 5), (1, 1, 6), (2, 1, 4), (1, 2, 5), (1, 4, 11), (1, 3, 8), and (7, 6, 32). The stability of these species, expressed by the equilibrium: pAl3+ + qCH3Sn3+ + rOH− = Alp(CH3Sn)q(OH)r 3(p+q)−r, βpqr OH, can be modeled by the empirical relationship: log βpqr OH = −3.34 + 2.67p + 9.23(q + r). By using the equilibrium constant Xpqr relative to the formation reaction: pAl(p+q)(OH)r + q(CH3Sn)(p+q)(OH)r = (p + q)Alp(CH3Sn)q(OH)r, it was found that the formation of heterometal mixed species is thermodynamically favored, and the extra stability can be expressed as a function of the difference in the stability of parent homometal species. This leads, in turn, to a significant enhancement of hydrolysis and solubility

Operative Treatment and Clinical Outcomes in Peripheral Vascular Trauma: The Combined Experience of Two Centers in the Endovascular Era

Background: Arterial traumas of the extremities are quite rare in civilian records; nevertheless, patients with trauma of limbs are admitted daily in emergency departments worldwide. The upto-date information about epidemiology and treatment (open vs. endovascular surgery) comes from war records and it is not always easy getting data on mortality and morbidity in these patients. The aim of this study is to analyze the approach (open or endovascular) and the outcome of patients with vascular trauma of upper limbs (from the subclavian artery) and/or lower limbs (distal to the inguinal ligament), in the greater Milan area. Methods: A retrospective analysis was conducted on data recorded by the emergency departments of two hospitals of the greater Milan between 2009 and 2017. We collected all patients with arterial injuries of the limbs in terms of demography, injury patterns, clinical status at admission, therapy (open or endovascular approach), and outcomes in terms of limb salvage and survival. Results: We studied 52 patients with vascular trauma of extremities. The main mechanism of trauma was road accident (48.1%), followed by criminal acts (32.7%), self-endangering behavior (13.5%), work (3.8%), and sport accidents (1.9%). Associated lesions (orthopedic, neurological, and/or venous lesions of the limbs) were present in 39 patients (75%). All patients underwent emergency surgery, forty-six patients (88.5%) by open repair (polytetrafluoroethylene or greater saphenous vein bypass grafts, arterial suture or ligation), whereas endovascular approach was used only in 6 patients (11.5%), all treated with embolization. The overall postoperative mortality rate was 5.7% (3 patients). Among survivors, we report 5 major amputations of the lower limbs, 3 of them after bypass graft infection, and 2 after graft failure. The rate of limb salvage was 90.4%. Conclusions: Isolated arterial trauma of the extremities are rare, usually they occur in the setting of multiple trauma patients. Despite progresses in surgical techniques, there are still controversies in diagnosis and treatment of these patients. We treated most cases with open surgery (n = 46), choosing endovascular approach (embolization performed mainly by interventional radiologists) in difficult anatomic districts. We believe that, during decision-making of the surgical strategy, it is important to consider the anatomical site of lesions and the general condition of the patients. Moreover, in case of multiple trauma, we suggest a multidisciplinary approach to provide the best medical care to the victims

Photodynamic Surgery for Feline Injection-Site Sarcoma

Musculoskeletal sarcomas are rare and aggressive human malignancies affecting bones and soft tissues with severe consequences, in terms of both morbidity and mortality. An innovative technique that combines photodynamic surgery (PDS) and therapy (PDT) with acridine orange has been recently suggested, showing promising results. However, due to the low incidence of sarcoma in humans, this procedure has been attempted only in pilot studies and stronger evidence is needed. Naturally occurring tumors in cats are well-established and advantageous models for human cancers. Feline injection-site sarcoma (FISS) shares with human musculoskeletal sarcomas a mesenchymal origin and an aggressive behavior with a high relapse rate. Furthermore, wide surgical excision is not always possible due to the size and site of development. We assessed the feasibility and the effectiveness of PDS and PDT with acridine orange to prevent FISS recurrence by treating a short case series of cats. For PDS, the surgical field was irrigated with an acridine orange solution and exposed to UV light to enlighten the residual tumor tissue, and the resultant fluorescent areas were trimmed. For PDT, before wound closure, the field was again irrigated with acridine orange solution and exposed to visible light to get the antitumoral cytocidal effect. The procedure was easy to perform and well tolerated, we did not observe any major complications, and all the surgical resection margins were free of disease. Finally, at follow-up, all treated patients did not show evidence of tumor recurrence and had a significantly higher event-free survival rate in respect to a control group treated only by surgery. In conclusion, by this study we demonstrated that, in FISS, PDS and PDT with acridine orange may improve local tumor control, granting a better outcome, and we laid the foundation to validate its effectiveness for the treatment of human musculoskeletal sarcomas

8-hydroxyquinoline-2-carboxylic acid as possible molybdophore: A multi-technique approach to define its chemical speciation, coordination and sequestering ability in aqueous solution

8-hydroxyquinoline-2-carboxylic acid (8-HQA) has been found in high concentrations (0.5–5.0 mmol·dm−3) in the gut of Noctuid larvae (and in a few other lepidopterans), in which it is proposed to act as a siderophore. Since it is known that many natural siderophores are also involved in the uptake and metabolism of other essential elements than iron, this study reports some results on the investigation of 8-HQA interactions with molybdate (MoO42−, i.e., the main molybdenum form in aqueous environments), in order to understand the possible role of this ligand as molybdophore. A multi-technique approach has been adopted, in order to derive a comprehensive set of information necessary to assess the chemical speciation of the 8-HQA/MoO42− system, as well as the coordination behavior and the sequestering ability of 8-HQA towards molybdate. Chemical speciation studies have been performed in KCl(aq) at I = 0.2 mol·dm−3 and T = 298.15 K by ISE-H+ (glass electrode) potentiometric and UV/Vis spectrophotometric titrations. CV (Cyclic Voltammetry), DP-ASV (Differential Pulse-Anodic Stripping Voltammetry), ESI-MS experiments and quantum mechanical calculations have been also performed to derive information about the nature and possible structure of species formed. These results are also compared with those reported for the 8-HQA/Fe3+ system in terms of chemical speciation and sequestering ability of 8HQA

Chelating Agents for the Sequestration of Mercury(II) and Monomethyl Mercury(II)

Both mercury(II) and monomethyl mercury(II) poisonings are of great concern for several reasons. As it happens for other metals, chelation therapy is the most indicated treatment for poisoned patients. The efficacy of the therapy and the reduction of side-effects can be sensibly enhanced by an accurate knowledge of all the physiological mechanisms involved in metal uptake, transport within and between various tissues, and (possibly) clearance. All these aspects, however, are strictly dependent on the chemical speciation (i.e., the distribution of the chemical species of a component in a given system) of both the metal and the chelating agent in the systems where they are present. In this light, this review analyzes the state of the art of research performed in this field for mercury(II) and methylmercury(II). After a brief summary of their main sources, the physiological patterns for the treatment of mercury poisoning have also been considered. The binding ability of various chelating agents toward mercury has been then analyzed by modeling the behavior of the main classes of ligands present in biological fluids and/or frequently used in chelation therapy. Their sequestering ability has been successively evaluated by means of a semiempirical parameter already proposed for its objective quantification, and the main characteristics of an efficient chelating agent have been evaluated on this basis