Anticancer Ruthenium(III) Complex KP1019 Interferes with ATP‐Dependent Ca2+ Translocation by Sarco‐Endoplasmic Reticulum Ca2+‐ATPase (SERCA)

Sarco‐endoplasmic reticulum Ca²⁺‐ATPase (SERCA), a P‐type ATPase that sustains Ca²⁺ transport and plays a major role in intracellular Ca²⁺ homeostasis, represents a therapeutic target for cancer therapy. Here, we investigated whether ruthenium‐based anticancer drugs, namely KP1019 (indazolium [trans‐tetrachlorobis(1H‐indazole)ruthenate(III)]), NAMI‐A (imidazolium [trans‐tetrachloro(1H‐imidazole)(S‐dimethylsulfoxide)ruthenate(III)]) and RAPTA‐C ([Ru(η⁶‐p‐cymene)dichloro(1,3,5‐triaza‐7‐phosphaadamantane)]), and cisplatin (cis‐diammineplatinum(II) dichloride) might act as inhibitors of SERCA. Charge displacement by SERCA adsorbed on a solid‐supported membrane was measured after ATP or Ca²⁺ concentration jumps. Our results show that KP1019, in contrast to the other metal compounds, is able to interfere with ATP‐dependent translocation of Ca²⁺ ions. An IC₅₀ value of 1 μM was determined for inhibition of calcium translocation by KP1019. Conversely, it appears that KP1019 does not significantly affect Ca²⁺ binding to the ATPase from the cytoplasmic side. Inhibition of SERCA at pharmacologically relevant concentrations may represent a crucial aspect in the overall pharmacological and toxicological profile of KP1019.     

Low band gap poly(1,4-arylene-2,5-thienylene)s with benzothiadiazole units: Synthesis, characterization and application in polymer solar cells

We describe the synthesis of two novel poly(1,4-arylene-2,5-thienylene)s P1 and P2 containing benzo[c][2,1,3]thiadiazole monomeric units via Suzuki-Miyaura polymerization of a thiophene diboronic ester with aryl diiodides. The use of a catalyst complex consisting of Pd(OAc)₂ in combination with the electron-rich biaryl phosphine S-Phos resulted in efficient polymerization reactions. The polymers synthesized, P1 and P2, were characterized by UV-vis spectroscopy and cyclic voltammetry. Theoretical calculations and electrochemical measurements on P1 suggested a favorable position of the molecular orbitals for employment in polymer solar cells in combination with PCBM. Devices containing P1:PCBM 1:2 in the active layer showed an efficiency of 1.2% by simple spin casting from chloroform.     

Strain-rate effects on concrete behavior

In this paper, a previously developed meso-scale model for concrete, called the Confinement Shear Lattice (CSL) model, is extended in order to include the effect of loading rate on concrete strength and fracturing behavior. The rate dependence of concrete behavior is assumed to be caused by two different physical mechanisms. The first is a dependence of the fracture process on the rate of crack opening, and the second is the viscoelastic deformation of the intact (unfractured) cement paste. In this study, the first mechanism is described by the activation energy theory applied to the ruptures occurring along the crack surfaces, whereas the second mechanism is modeled by the Microprestress-Solidification theory. The developed model is calibrated and validated on the basis of experimental data gathered from the literature.     

Lattice Discrete Particle Model (LDPM) for failure behavior of concrete. I: Theory

This paper deals with the formulation, calibration, and validation of the Lattice Discrete Particle Model (LDPM) suitable for the simulation of the failure behavior of concrete. LDPM simulates concrete at the meso-scale considered to be the length scale of coarse aggregate pieces. LDPM is formulated in the framework of discrete models for which the unknown displacement field is not continuous but only defined at a finite number of points representing the center of aggregate particles. Size and distribution of the particles are obtained according to the actual aggregate size distribution of concrete. Discrete compatibility and equilibrium equations are used to formulate the governing equations of the LDPM computational framework. Particle contact behavior represents the mechanical interaction among adjacent aggregate particles through the embedding mortar. Such interaction is governed by meso-scale constitutive equations simulating meso-scale tensile fracturing with strain-softening, cohesive and frictional shearing, and nonlinear compressive behavior with strain-hardening. The present, Part I, of this two-part study deals with model formulation leaving model calibration and validation to the subsequent Part II.     

Modeling of thin-film slurry photocatalytic reactors affected by radiation scattering

Photocatalytic oxidation over titanium dioxide is a "green" sustainable process for treatment and purification of water and wastewater. A dimensionless model for steady-state, continuous flow, thin-film, slurry (TFS) photocatalytic reactors for water purification using solar radiation and UV lamps is presented and validated. The model is applicable to TFS flat plate and annular photoreactors of (a) falling film or (b) double-skin designs, operating with three ideal flows: (1) falling film laminar flow (FFLF), (2) plug flow (PF) and (3) slitflow (SF). Model parameters can be estimated easily from real systems, and solutions can be obtained with modest computational efforts. A modified two-flux absorption-scattering model models the radiation field in the photoreactor. Model simulations show that at a scattering albedo higher than 0.3, radiation scattering can significantly affect conversions obtained at different values of optical thickness. However, at lower values, the effect of scattering on conversions is negligible. The conversions with the idealized flow systems follow the sequence FFLF > PF > SF. SF operation should always be avoided. The model estimates the optimum value of optical thickness that maximizes conversion in a photocatalytic reactor. Optimal design of TFS photocatalytic reactors using the photocatalyst TiO2 Degussa P25 requires an optical thickness in the range from 1.8 to 3.4 depending on flow conditions and reaction kinetics.     

Autoimmune Neutropenia and Immune-Dysregulation in a Patient Carrying a TINF2 Variant

In recent years, the knowledge about the immune-mediated impairment of bone marrow precursors in immune-dysregulation and autoimmune disorders has increased. In addition, immune-dysregulation, secondary to marrow failure, has been reported as being, in some cases, the most evident and early sign of the disease and making the diagnosis of both groups of disorders challenging. Dyskeratosis congenita is a disorder characterized by premature telomere erosion, typically showing marrow failure, nail dystrophy and leukoplakia, although incomplete genetic penetrance and phenotypes with immune-dysregulation features have been described. We report on a previously healthy 17-year-old girl, with a cousin successfully treated for acute lymphoblastic leukemia, who presented with leukopenia and neutropenia. The diagnostic work-up showed positive anti-neutrophil antibodies, leading to the diagnosis of autoimmune neutropenia, a slightly low NK count and high TCR-αβ+-double-negative T-cells. A next-generation sequencing (NGS) analysis showed the 734C>A variant on exon 6 of the TINF2 gene, leading to the p.Ser245Tyr. The telomere length was short on the lymphocytes and granulocytes, suggesting the diagnosis of an atypical telomeropathy showing with immune-dysregulation. This case underlines the importance of an accurate diagnostic work-up of patients with immune-dysregulation, who should undergo NGS or whole exome sequencing to identify specific disorders that deserve targeted follow-up and treatment.     

Modeling RTT Syndrome by iPSC-Derived Neurons from Male and Female Patients with Heterogeneously Severe Hot-Spot MECP2 Variants

Rett syndrome caused by MECP2 variants is characterized by a heterogenous clinical spectrum accounted for in 60% of cases by hot-spot variants. Focusing on the most frequent variants, we generated in vitro iPSC-neurons from the blood of RTT girls with p.Arg133Cys and p.Arg255*, associated to mild and severe phenotype, respectively, and of an RTT male harboring the close to p.Arg255*, p.Gly252Argfs*7 variant. Truncated MeCP2 proteins were revealed by Western blot and immunofluorescence analysis. We compared the mutant versus control neurons at 42 days for morphological parameters and at 120 days for electrophysiology recordings, including girls’ isogenic clones. A precocious reduced morphological complexity was evident in neurons with truncating variants, while in p.Arg133Cys neurons any significant differences were observed in comparison with the isogenic wild-type clones. Reduced nuclear size and branch number show up as the most robust biomarkers. Patch clamp recordings on mature neurons allowed the assessment of cell biophysical properties, V-gated currents, and spiking pattern in the mutant and control cells. Immature spiking, altered cell capacitance, and membrane resistance of RTT neurons, were particularly pronounced in the Arg255* and Gly252Argfs*7 mutants. The overall results indicate that the specific markers of in vitro cellular phenotype mirror the clinical severity and may be amenable to drug testing for translational purposes.     

Top-Down Preparation of Nanoquartz for Toxicological Investigations

Occupational exposure to quartz dust is associated with fatal diseases. Quartz dusts generated by mechanical fracturing are characterized by a broad range of micrometric to nanometric particles. The contribution of this nanometric fraction to the overall toxicity of quartz is still largely unexplored, primarily because of the strong electrostatic adhesion forces that prevent isolation of the nanofraction. Furthermore, fractured silica dust exhibits special surface features, namely nearly free silanols (NFS), which impart a membranolytic activity to quartz. Nanoquartz can be synthetized via bottom-up methods, but the surface chemistry of such crystals strongly differs from that of nanoparticles resulting from fracturing. Here, we report a top-down milling procedure to obtain a nanometric quartz that shares the key surface properties relevant to toxicity with fractured quartz. The ball milling was optimized by coupling the dry and wet milling steps, using water as a dispersing agent, and varying the milling times and rotational speeds. Nanoquartz with a strong tendency to form submicrometric agglomerates was obtained. The deagglomeration with surfactants or simulated body fluids was negligible. Partial lattice amorphization and a bimodal crystallite domain size were observed. A moderate membranolytic activity, which correlated with the number of NFS, signaled coherence with the previous toxicological data. A membranolytic nanoquartz for toxicological investigations was obtained.     

Serratiopeptidase Affects the Physiology of Pseudomonas aeruginosa Isolates from Cystic Fibrosis Patients

Pseudomonas aeruginosa is frequently involved in cystic fibrosis (CF) airway infections. Biofilm, motility, production of toxins and the invasion of host cells are different factors that increase P. aeruginosa’s virulence. The sessile phenotype offers protection to bacterial cells and resistance to antimicrobials and host immune attacks. Motility also contributes to bacterial colonization of surfaces and, consequently, to biofilm formation. Furthermore, the ability to adhere is the prelude for the internalization into lung cells, a common immune evasion mechanism used by most intracellular bacteria, such as P. aeruginosa. In previous studies we evaluated the activity of metalloprotease serratiopeptidase (SPEP) in impairing virulence-related properties in Gram-positive bacteria. This work aimed to investigate SPEP’s effects on different physiological aspects related to the virulence of P. aeruginosa isolated from CF patients, such as biofilm production, pyoverdine and pyocyanin production and invasion in alveolar epithelial cells. Obtained results showed that SPEP was able to impair the attachment to inert surfaces as well as adhesion/invasion of eukaryotic cells. Conversely, SPEP’s effect on pyocyanin and pyoverdine production was strongly strain-dependent, with an increase and/or a decrease of their production. Moreover, SPEP seemed to increase swarming motility and staphylolytic protease production. Our results suggest that a large number of clinical strains should be studied in-depth before drawing definitive conclusions. Why different strains sometimes react in opposing ways to a specific treatment is of great interest and will be the object of future studies. Therefore, SPEP affects P. aeruginosa’s physiology by differently acting on several bacterial factors related to its virulence.     

Using a neural network for predicting the average grain size in friction stir welding processes

In the paper the microstructural phenomena in terms of average grain size occurring in friction stir welding (FSW) processes are focused. A neural network was linked to a finite element model (FEM) of the process to predict the average grain size values. The utilized net was trained starting from experimental data and numerical results of butt joints and then tested on further butt, lap and T-joints. The obtained results show the capability of the AI technique in conjunction with the FE tool to predict the final microstructure in the FSW joints.