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Ferroptosis is a non-accidental, regulated form of cell death operated by lipid peroxidation under strict control of GPx4 activity. This is consistent with the notion that lipid peroxidation is initiated by radicals produced from decomposition of traces of pre-existing lipid hydroperoxides. The question, therefore, emerges about the formation of these traces of lipid hydroperoxides interacting with Fe2+. In the most realistic option, they are produced by oxygen activated species generated during aerobic metabolism. Screening for metabolic sources of superoxide supporting ferroptosis induced by GSH depletion, we failed to detect, in our cell model, a role of respiratory chain. We observed instead that the pyruvate dehydrogenase complex -as other α keto acid dehydrogenases already known as a major source of superoxide in mitochondria- supports ferroptosis. The opposite effect on ferroptosis by silencing either the E1 or the E3 subunit of the pyruvate dehydrogenase complex pointed out the autoxidation of dihydrolipoamide as the source of superoxide. We finally observed that GSH depletion activates superoxide production, seemingly through the inhibition of the specific kinase that inhibits pyruvate dehydrogenase. In summary, this set of data is compatible with a scenario where the more electrophilic status produced by GSH depletion not only activates ferroptosis by preventing GPx4 activity, but also favors the formation of lipid hydroperoxides. In an attractive perspective of tissue homeostasis, it is the activation of energetic metabolism associated to a decreased nucleophilic tone that, besides supporting energy demanding proliferation, also sensitizes cells to a regulated form of death.

Purpose The diagnosis of vitamin D deficiency is based on the determination of total plasma 25-hydroxyvitamin D (25-OHD) concentrations, but the regulation of vitamin D 25-hydroxylation is not a major consideration and very little information is available on this activity. To check what factors could interfere with the activity of vitamin D-25-hydroxylase and thus alter the 25-OHD concentrations, we looked for potential correlations between 25-OHD and results of liver function tests in healthy adults. Methods This single-centre study was retrospective and consisted of evaluating the correlations between 25-OHD and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and bone alkaline phosphatase (BALP) in 349 healthy subjects aged from 18 to 65 years. In particular, in Group 1 (n = 119), we looked for correlations between 25OHD and all liver function tests and in Group 2 (n = 230) the correlation between 25OHD and BALP. Results In Group 1, we found no correlation between 25OHD and AST (r = − 0.03; p = 0.8), ALT (r = − 0.02; p = 0.91), GGT (r = − 0.08; p = 0.68), direct bilirubin (r = − 0.02; p = 0.89), indirect bilirubin (r = − 0.24; p = 0.21), and total bilirubin (r = − 0.24; p = 0.21) but one between 25OHD and ALP (r = − 0.2; p = 0.007); in Group 2, we found a significant negative correlation between 25-OHD and BALP (r = − 0.2; p = 0.0008). Conclusions The correlations that we found suggest that ALP and BALP might be involved in the regulation of vitamin D-25-hydroxylase activity, but further studies are mandatory to confirm our assumptions.

A meta-analysis of cardiorenal outcomes of sodium-glucose co-transporter-2 inhibitors (SGLT-2is) available in Europe or the United States in patients with type 2 diabetes (T2D) is presented. An electronic search up to 6 January 2021 was conducted to determine eligible trials. A total of eight cardiorenal outcomes trials of SGLT-2is (empagliflozin, canagliflozin, dapagliflozin, ertugliflozin and sotagliflozin) were identified, with 65,587 patients. Data were analysed using a random effects model. Overall, SGLT-2is were associated with a 12% reduced risk of major adverse cardiovascular events (MACE; HR = 0.88; 95% CI, 0.83-0.93; Q statistic, p = .19), with no significant heterogeneity (p for interaction = .465) between subgroups of patients with or without cardiovascular disease (CVD). The risk of the composite renal outcome was significantly reduced by treatment with SGLT-2is (HR = 0.61, 95% CI, 0.54-0.70), with no significant heterogeneity of associations with outcome (I2 = 37%, p = .11), and no difference in the risk between patients with or without CVD (p for interaction = .665). SGLT-2is have moderate benefits on MACE and major benefits on the progression of diabetic kidney disease.

Background: Abnormal liver blood tests (LBTs) in hyperthyroid patients are not uncommonly encountered. One major adverse event of antithyroid drug (ATD) therapy is drug-induced hepatotoxicity. Abnormal LBT in the hyperthyroidism scenario is a main diagnostic and therapeutic dilemma. We aimed to assess the prevalence and the response to ATD therapy of LBT abnormalities in newly diagnosed and uncomplicated hyperthyroidism through a systematic review and meta-analysis. Methods: A literature search was performed reporting LBTs at presentation and after ATD therapy in hyperthyroid patients. A proportion meta-analysis was performed with random-effects model. Pooled data were presented with 95% confidence intervals (CI). I2 statistic index was used to quantify the heterogeneity. Sensitivity analyses for prevalence of hyperthyroid patients with at least one abnormal LBT were performed. p-Value of

Selenoproteins are translated via animal domain-specific elongation machineries that redefine dedicated UGA opal codons from termination of translation to selenocysteine (Sec) insertion, utilizing specific tRNA species and Sec-specific elongation factors. This has made recombinant production of mammalian selenoproteins in E. coli technically challenging but recently we developed a methodology that enables such production, using recoding of UAG for Sec in an RF1-deficient host strain. Here we used that approach for production of the human glutathione peroxidases 1, 2 and 4 (GPX1, GPX2 and GPX4), with all these three enzymes being important antioxidant selenoproteins. Among these, GPX4 is the sole embryonically essential enzyme, and is also known to be essential for spermatogenesis as well as protection from cell death through ferroptosis. Enzyme kinetics, ICP-MS and mass spectrometry analyses of the purified recombinant proteins were used to characterize selenoprotein characteristics and their Sec contents. This revealed a unique phenomenon of one-codon skipping, resulting in a lack of a single amino acid at the position corresponding to the selenocysteine (Sec) residue, in about 30% of the recombinant GPX isoenzyme products. We furthermore confirmed the previously described UAG suppression with Lys or Gln as well as a minor suppression with Tyr, together resulting in about 20% Sec contents in the full-length proteins. No additional frameshifts or translational errors were detected. We subsequently found that Sec-containing GPX4 could be further purified over a bromosulfophthalein-column, yielding purified recombinant GPX4 with close to complete Sec contents. This production method for homogenously purified GPX4 should help to further advance the studies of this important selenoprotein.

Temporal RNA-seq data reveal genomic signatures of the unjamming transition in compressed human bronchial epithelial cells., Epithelial tissue can transition from a jammed, solid-like, quiescent phase to an unjammed, fluid-like, migratory phase, but the underlying molecular events of the unjamming transition (UJT) remain largely unexplored. Using primary human bronchial epithelial cells (HBECs) and one well-defined trigger of the UJT, compression mimicking the mechanical effects of bronchoconstriction, here, we combine RNA sequencing data with protein-protein interaction networks to provide the first genome-wide analysis of the UJT. Our results show that compression induces an early transcriptional activation of the membrane and actomyosin network and a delayed activation of the extracellular matrix (ECM) and cell-matrix networks. This response is associated with a signaling cascade that promotes actin polymerization and cellular motility through the coordinated interplay of downstream pathways including ERK, JNK, integrin signaling, and energy metabolism. Moreover, in nonasthmatic versus asthmatic HBECs, common genomic patterns associated with ECM remodeling suggest a molecular connection between airway remodeling, bronchoconstriction, and the UJT.

Aims GIOIA is an ongoing prospective multicentre study aiming to assess the vascular and metabolic effects of SGLT-2 inhibitors (gliflozins) and DPP-4 inhibitors (gliptins) in the routine clinical practice of patients with type 2 diabetes (T2D). Herein we describe the preliminary effectiveness data at 6 months. Methods SGLT-2i and DPP-4i-naive adult patients with T2D (N = 301 and 260, respectively), with glycated haemoglobin A1c (A1C) >7%, an estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2, on background therapy with metformin, insulin or both, are being followed to evaluate markers of vascular (carotid intima-media thickness), myocardial (myocardial diastolic function) and renal (urinary albumin/creatinine ratio) damage during treatment with SGLT-2i or DPP-4i for a period of 24 months. Result At baseline, patients initiated on SGLT-2i are younger (about 6 years) and more heavy (about 7.5 kg), have higher A1C level (0.5% more), a longer diabetes duration and more CV events (20% more) than patients initiated on DPP‐4i. At 6 months, patients on SGLT-2i (N = 298) and DPP-4i (N = 258) exhibit significant ameliorations in A1C (−1.% and −0.7%, respectively), which were greater (−1.2% and −0.81%) in those on a background metformin treatment only. The composite endpoint (A1C ≤ 7.0% + weight loss ≥ 3 kg) was achieved by 24% and 16% of patients receiving SGLT-2i or DPP-4i, respectively. No unexpected adverse events were reported. Conclusions Both SGLT-2i and DPP-4i provide substantial improvements in metabolic parameters in the usual clinical practice of T2D, especially when used as second-line treatment.

Phase Change Materials (PCMs) incorporated in refrigerators can be used to shift their energy consumption from peak periods, when the electric network energy demand is the highest, to off-peak periods. While PCMs can flatten the energy demand curve, they can achieve economic savings if Time-of-Use (TOU) electricity tariffs are applied. However, the hourly carbon emission factor is not commonly linked to the hourly tariff, and the final CO2 emitted due to the operations of the refrigerator would not be fully optimized. In this work, a method based on the Simulated Annealing optimization technique was proposed to identify the optimal working schedule of a cabinet refrigerator incorporating a PCM to reduce its indirect carbon emissions. Data from countries with different representative carbon intensity profiles were used. The normalized standard deviation and normalized range are the best statistical indexes to predict carbon emission reduction in the proposed solution. These parameters proved that countries with a higher hourly carbon intensity variation (Uruguay, France, Denmark, and Germany) benefit from the application of the algorithm. Cost and carbon emission reduction cannot be maximized simultaneously, and a trade-off is required.

Charged particle radiotherapy is currently used in an increasing number of centres worldwide. While protons are the most widely used ion species, carbon ions have shown many advantages for the treatment of radioresistant tumours, thanks to their higher Linear Energy Transfer (LET) and Relative Biological Effectiveness (RBE). The complexity and the high cost of conventional carbon therapy facilities has stimulated the investigation of alternative acceleration approaches such as the processes based on high-power laser interaction with solid targets. Recent developments in ion acceleration have allowed to investigate for the first time the biological effects of carbon ions at ultra-high dose-rate (109-1010 Gy/s) using the GEMINI laser system at Rutherford Appleton Laboratory (RAL). Carbon ions were accelerated from ultrathin (10-20 nm) carbon foils and energy selected by a magnet allowing to irradiate the cells with an average carbon energy of 10 MeV/u ± 8%. A dosimetry approach specifically designed for these low-energy ions was employed, which was based on the use of unlaminated EBT3 Radiochromic films. The details of the dosimetry arrangement as well as the Geant4 simulation performed to predict the energy and the dose distribution at the cell plane will be reported.

Epithelial tissue has the capacity to switch from a collective phase that is quiescent, solidlike and non-migratory to one that is dynamic, fluid-like and migratory. In certain physiological and pathophysiological contexts this phenotypic switch has been attributed not to the well-known epithelial-to-mesenchymal transition, EMT, but rather to the recently discovered unjamming transition, UJT. UJT has been characterized thus far mainly at functional and morphological levels whereas underlying genome-wide molecular events remain largely unexplored. Using primary human bronchial epithelial cells and one well-defined trigger of UJT –mechanical compression– here we combine temporal RNA-Seq data and Protein-Protein Interaction networks to provide the first genome-wide analysis of UJT. Our results show that compression induces a multiphasic transcriptional response characterized by an early activation of genes regulating the membrane and actomyosin structure, and a delayed activation of genes regulating the extracellular matrix and cellmatrix interactions. This biphasic response is mediated by a cascade of signaling processes that promotes actin polymerization through the recruitment of integrin-ECM adhesive complexes and promotes increased cellular motility through activation of AP-1 transcription factors via ERK and JNK pathways. These findings, taken together, show that the UJT program is not the result of any single signaling pathway but rather comprises a coordinated interplay of downstream pathways including development, fate selection, energy metabolism, cytoskeletal reorganization, and adhesive interaction with extracellular matrix.

A high-dynamic-range reflectivity measurement instrument has been developed with a dynamic range in excess of 100 dB and sensitivity below 1 pW. It can measure the angle-dependent back-scattered reflectivity of static surfaces up to 80o incidence angle over any orientation without the need for physical contact with the part. It has been designed to operate at both 800 nm and 1550 nm. The system operates through lock-in detection of amplitude-modulated laser light in a bi-static probe architecture, specially designed to minimise the effects of unwanted scattering and stray light. This development has been designed for on-site characterisation of the reflectivity of components of the ITER nuclear fusion reactor whose size, radioactivity or toxicity are inappropriate for insertion in traditional BRDF measurement instrumentation. Measuring the reflectivity of these components is critical for the development of tools for in-service inspection of ITER’s reaction chamber, a key element for the safety of the machine. The reflectivity of beryllium blanket module components and tungsten divertor components has been measured to vary over a range of up to 50 dB from normal to 80o incidence angle, to values below 10-5 /sr. Strong anisotropy of the reflectivity is also observed. This data has been matched with the inspection system performance in a custom simulator to confirm that inspection is possible over < 95 % of the ITER reactor plasma facing components.

The (seleno)cysteine residues in some protein families react with hydroperoxides with rate constants far beyond those of fully dissociated low molecular weight thiol or selenol compounds. In case of the glutathione peroxidases, we could demonstrate that high rate constants are achieved by a proton transfer from the chalcogenol to a residue of the active site [Orian et al. Free Radic. Biol. Med. 87 (2015)]. We extended this study to three more protein families (OxyR, GAPDH and Prx). According to DFT calculations, a proton transfer from the active site chalcogenol to a residue within the active site is a prerequisite for both, creating a chalcogenolate that attacks one oxygen of the hydroperoxide substrate and combining the delocalized proton with the remaining OH or OR, respectively, to create an ideal leaving group. The “parking postions” of the delocalized proton differ between the protein families. It is the ring nitrogen of tryptophan in GPx, a histidine in GAPDH and OxyR and a threonine in Prx. The basic principle, however, is common to all four families of proteins. We, thus, conclude that the principle outlined in this investigation offers a convincing explanation for how a cysteine residue can become peroxidatic., Graphical abstract Image 1, Highlights • In some protein families, (seleno)cysteine residues react with hydroperoxides with very high rate constants. • In GPx, DFT models of the oxidation of the catalytic site support a two-step mechanism for the H2O2 reduction. • This mechanism is here found to operate in other thiol-based enzymes, i.e. OxyR, GAPDH and Prx.

This work presents a neutronic assessment to convert a Small Modular Reactor (SMR) with uranium core to the thorium mixed oxide core with minimum possible changes in the geometry and main parameters of SMR core. This option is due to most of SMR are designed to be strongly poisoned in the beginning of cycle and to have a long cycle. Thorium can be used as an absorber in the beginning of the cycle and also be used as a fertile material during the cycle, it seems to be a good option to use (Th/U)O2 as SMR’s fuel. The main neutronic objectives of this study is achieving longer cycle length for SMR by using the minimum possible amount of burnable poison and soluble boron in comparison with reference core. The Korean SMART reactor as a certified design SMR has been chosen as the reference core. The calculations have been performed by MCNP code for homogeneous and heterogeneous seed and blanket concept fuel assemblies. The results obtained show that the heterogeneous fuel assembly is the one which gives longer cycle length and used lower amount of burnable poison and soluble boron, and also consumes almost the same amount of 235U.

Iron-dependent lipid peroxidation is a complex oxidative process where phospholipid hydroperoxides (PLOOH) are produced in membranes and finally transformed into a series of decomposition products, some of which are endowed with biological activity. It is specifically prevented by glutathione peroxidase 4 (GPx4), the selenoenzyme that reduces PLOOH by glutathione (GSH). PLOOH is both a product and the major initiator of peroxidative chain reactions, as well as an activator of lipoxygenases. α-Tocopherol both specifically breaks peroxidative chain propagation and inhibits lipoxygenases. Thus, GPx4, GSH, and α-tocopherol are integrated in a concerted anti-peroxidant mechanism. Recent Advances: Ferroptosis has been recently identified as a cell death subroutine that is specifically activated by missing GPx4 activity and inhibited by iron chelation or α-tocopherol supplementation. Ferroptosis induction may underlie spontaneous human diseases, such as major neurodegeneration and neuroinflammation, causing an excessive cell death. The basic mechanism of ferroptosis, therefore, fits the features of activation of lipid peroxidation.Still lacking are convincing proofs that lipoxygenases are involved in ferroptosis. Also, unknown are the molecules eventually killing cells and the mechanisms underlying the drop of the cellular anti-peroxidant capacity.Molecular events and mechanisms of ferroptosis to be unraveled and validated on animal models are GPx4 inactivation, role of GSH concentration, increased iron availability, and membrane structure and composition. This is expected to drive drug discovery that is aimed at halting cell death in degenerative diseases or boosting it in cancer cells. Antioxid. Redox Signal. 29, 61-74.

Diabetic kidney disease (DKD) still remains a progressive condition that is associated with higher risk of end-stage kidney disease and significant cardiovascular morbidity and mortality. Twelve cardiovascular outcome trials in type 2 diabetes (T2D) have been published to date. Most trials with dipeptidyl-peptidase inhibitors (SAVOR-TIMI 53 with saxagliptin, EXAMINE with alogliptin, TECOS with sitagliptin, and CARMELINA with linagliptin) and with glucagon-like peptide-1 receptor agonists (GLP-1RAs) (ELIXA with lixisenatide, LEADER with liraglutide, SUSTAIN-6 with semaglutide, EXCSEL with exenatide once-weekly, and HARMONY with albiglutide) pointed towards reduced albuminuria, which is a surrogate endpoint possibly heralding renal function preservation. The three trials with sodium-glucose co-transporter-2 inhibitors (SGLT-2is) (empagliflozin, canagliflozin and dapagliflozin) also showed a salutary effect on long-term estimated glomerular filtration rate, suggesting that SGLT-2is are more effective at mitigating loss of kidney function than incretin-based therapies; moreover, SGLT-2is also have the advantage of plausible haemodynamic mechanisms for improved renal outcomes. Despite some residual limitations linked to differences in study populations and patient characteristics, the cardiorenal protective actions of SGLT-2is, and to a lesser extent some GLP-1RAs, make them favourable medications for patients with T2D at increased cardiorenal risk. There is room for optimism that their use may change the paradigm of the ineluctable progression of DKD.

This work presents the neutronics and thermal hydraulics feasibility to convert the UO 2 core of the Westinghouse AP1000 in a (U-Th)O 2 core by performing a parametric study varying the type of geometry of the pins in fuel elements, using the heterogeneous seed blanket concept and the homogeneous concept. In the parametric study, all geometry and materials for the burnable poison were kept the same as the AP 1000, and the only variable was the fuel pin material, in which we use several mass proportion of uranium and thorium but keeping the enrichment in 235 U, as LEU (20 w/o). The neutronics calculations were made by SERPENT code, and to validate the thermal limits we used a homemade code. The optimization criteria were to maximize the 233 U, and conversion factor, and minimize the plutonium production. The results obtained showed that the homogeneous concept with three different mass proportion zones, the first containing (32% UO 2 -68%ThO 2 ); the second with (24% UO 2 -76% ThO 2 ), and the third with (20% UO 2 -80% ThO 2 ), using 235 U LEU (20 w/o), and corresponding with the 3 enrichment zones of the AP 1000 (4.45 w/o; 3.40 w/o; 2.35 w/o), satisfies the optimization criteria as well as attending all thermal constrain. The concept showed advantages compared with the original UO 2 core, such a lower power density, and keeping the same 18 months of cycle a reduction of B-10 concentration at the soluble poison as well as eliminating in the integral boron poison coated (IFBA).

Ferroptosis (FPT) is a form of cell death due to missed control of membrane lipid peroxidation (LPO). According to the axiomatic definition of non-accidental cell death, LPO takes place in a scenario of altered homeostasis. FPT, differently from apoptosis, occurs in the absence of any known specific genetically encoded death pathway or specific agonist, and thus must be rated as a regulated, although not "programmed", death pathway. It follows that LPO is under a homeostatic metabolic control and is only permitted when indispensable constraints are satisfied and the antiperoxidant machinery collapses. The activity of the selenoperoxidase Glutathione Peroxidase 4 (GPx4) is the cornerstone of the antiperoxidant defence. Converging evidence on both mechanism of LPO and GPx4 enzymology indicates that LPO is initiated by alkoxyl radicals produced by ferrous iron from the hydroperoxide derivatives of lipids (LOOH), traces of which are the unavoidable drawback of aerobic metabolism. FPT takes place when a threshold has been exceeded. This occurs when the major conditions are satisfied: i) oxygen metabolism leading to the continuous formation of traces of LOOH from phospholipid-containing polyunsaturated fatty acids; ii) missed enzymatic reduction of LOOH; iii) availability of ferrous iron from the labile iron pool. Although the effectors impacting on homeostasis and leading to FPT in physiological conditions are not known, from the available knowledge on LPO and GPx4 enzymology we propose that it is aerobic life itself that, while supporting bioenergetics, is also a critical requisite of FPT. Yet, when the homeostatic control of the steady state between LOOH formation and reduction is lost, LPO is activated and FPT is executed.

GPx8 is a glutathione peroxidase homolog inserted in the membranes of endoplasmic reticulum (ER), where it seemingly plays a role in controlling redox status by preventing the spill of H2O2. We addressed the impact of GPx8 silencing on the lipidome of microsomal membranes, using stably GPx8-silenced HeLa cells. The two cell lines were clearly separated by Principal Component Analysis (PCA) and Partial Least Square Discriminant analysis (PLS-DA) of lipidome. Considering in detail the individual lipid classes, we observed that unsaturated glycerophospholipids (GPL) decreased, while only in phosphatidylinositols (PI) a substitution of monounsaturated fatty acids (MUFA) for polyunsaturated fatty acids (PUFA) was observed. Among sphingolipids (SL), ceramides (CER) decreased while sphingomyelins (SM) and neutral glycophingolipids (nGSL) increased. Here, in addition, longer chains than in controls in the amide fatty acid were present. The increase up to four folds of the CER (d18:1 ; c24:0) containing three hexose units, was the most remarkable species increasing in the differential lipidome of siGPx8 cells. Quantitative RT-PCR complied with lipidomic analysis specifically showing an increased expression of: i) acyl-CoA synthetase 5 (ACSL5) ; ii) CER synthase 2 and 4 ; iii) CER transporter (CERT) ; iv) UDP-glucosyl transferase (UDP-GlcT), associated to a decreased expression of UDP- galactosyl transferase (UDP-GalT). A role of the unfolded protein response (UPR) and the spliced form of the transcription factor XBP1 on the transcriptional changes of GPx8 silenced cells was ruled-out. Similarly, also the involvement of Nrf2 and NF-κB. Altogether our results indicate that GPx8- silencing of HeLa yields a membrane depleted by about 24% of polyunsaturated GPL and a corresponding increase of saturated or monounsaturated SM and specific nGSL. This is tentatively interpreted as an adaptive mechanism leading to an increased resistance to radical oxidations. Moreover, the marked shift of fatty acid composition of PI emerges as a possibly relevant issue in respect to the impact of GPx8 on signaling pathways.

Ras-selective lethal small molecule 3 (RSL3), a drug candidate prototype for cancer chemotherapy, triggers ferroptosis by inactivating the glutathione peroxidase glutathione peroxidase 4 (GPx4). Here, we report the purification of the protein indispensable for GPx4 inactivation by RSL3. Mass spectrometric analysis identified 14-3-3 isoforms as candidates, and recombinant human 14-3-3e confirms the identification. The function of 14-3-3e is redox-regulated. Moreover, overexpression or silencing of the gene coding for 14-3-3e consistently controls the inactivation of GPx4 by RSL3. The interaction of GPx4 with a redox-regulated adaptor protein operating in cell signaling further contributes to frame it within redox-regulated pathways of cell survival and death and opens new therapeutic perspectives.

The concept of nanoparticle transport through gaps between endothelial cells (inter-endothelial gaps) in the tumour blood vessel is a central paradigm in cancer nanomedicine. The size of these gaps was found to be up to 2,000 nm. This justified the development of nanoparticles to treat solid tumours as their size is small enough to extravasate and access the tumour microenvironment. Here we show that these inter-endothelial gaps are not responsible for the transport of nanoparticles into solid tumours. Instead, we found that up to 97% of nanoparticles enter tumours using an active process through endothelial cells. This result is derived from analysis of four different mouse models, three different types of human tumours, mathematical simulation and modelling, and two different types of imaging techniques. These results challenge our current rationale for developing cancer nanomedicine and suggest that understanding these active pathways will unlock strategies to enhance tumour accumulation. The dominant mechanism of nanoparticle entry into solid tumours has now been shown to be an active trans-endothelial pathway rather than the currently established passive transport via inter-endothelial gaps.

Mutations in the TREM2 gene confer risk for Alzheimer's disease and susceptibility for Parkinson's disease (PD). We evaluated the effect of TREM2 deletion in a 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine (MPTP)–induced PD mouse model, measuring neurodegeneration and microglia activation using a combined invivo imaging and postmortem molecular approach. In wild-type mice, MPTP administration induced a progressive decrease of [11C]FECIT uptake, culminating at day 7. Neuronal loss was accompanied by an increase of TREM2, IL-1β, and translocator protein (TSPO) transcript levels, [11C]PK11195 binding and GFAP staining (from day 2), and an early and transient increase of TNF-α, Galectin-3, and Iba-1 (from day 1). In TREM2 null (TREM2−/−) mice, MPTP similarly affected neuron viability and microglial cells, as shown by the lower level of Iba-1 staining in basal condition, and reduced increment of Iba-1, TNF-α, and IL-1β in response to MPTP. Likely to compensate for TREM2 absence, TREM2−/− mice showed an earlier increment of [11C]PK11195 binding and a significant increase of IL-4. Taken together, our data demonstrate a central role of TREM2 in the regulation of microglia response to acute neurotoxic insults and suggest a potential modulatory role of TSPO in response to immune system deficit.

The importance of metabolic syndrome (MetS) lies in its associated risk of cardiovascular disease and type 2 diabetes, as well as other harmful conditions such as nonalcoholic fatty liver disease. In this report, the available scientific evidence on the associations between lifestyle changes and MetS and its components is reviewed to derive recommendations for MetS prevention and management. Weight loss through an energy-restricted diet together with increased energy expenditure through physical activity contribute to the prevention and treatment of MetS. A Mediterranean-type diet, with or without energy restriction, is an effective treatment component. This dietary pattern should be built upon an increased intake of unsaturated fat, primarily from olive oil, and emphasize the consumption of legumes, cereals (whole grains), fruits, vegetables, nuts, fish, and low-fat dairy products, as well as moderate consumption of alcohol. Other dietary patterns (Dietary Approaches to Stop Hypertension, new Nordic, and vegetarian diets) have also been proposed as alternatives for preventing MetS. Quitting smoking and reducing intake of sugar-sweetened beverages and meat and meat products are mandatory. Nevertheless, there are inconsistencies and gaps in the evidence, and additional research is needed to define the most appropriate therapies for MetS. In conclusion, a healthy lifestyle is critical to prevent or delay the onset of MetS in susceptible individuals and to prevent cardiovascular disease and type 2 diabetes in those with existing MetS. The recommendations provided in this article should help patients and clinicians understand and implement the most effective approaches for lifestyle change to prevent MetS and improve cardiometabolic health.

Carbon dioxide (R744) is as a valid alternative to classical substances such as HFCs used in vapour compression plants. A transcritical refrigeration cycle is needed because the critical temperature of carbon dioxide is usually lower than the ambient temperature. In this chapter the performances of a transcritical cycle have been evaluated with a prototype R744 system working as a classical spit-systems to cool air. An experimental analysis has been carried out on the effect of: refrigerant charge, internal heat exchanger, heat rejection pressure on the energetic performances of the transcritical plant. An experimental analysis of a hybrid trans-critical refrigerator-desiccant wheel system has been carried out in order to improve the COP. The experimental transcritical cycle has been examined in comparison with a classical vapour compression plant working with the R134a.

IL-27 and IL-35 are heterodimeric cytokines, members of the IL-12 family and considered to have immunomodulatory properties. Their role during neuroinflammation had been investigated using mutant mice devoid of either one of their subunits or lacking components of their receptors, yielding conflicting results. We sought to understand the therapeutic potential of IL-27 and IL-35 delivered by gene therapy in neuroinflammation. We constructed lentiviral vectors expressing IL-27 and IL-35 from a single polypeptide chain, and we validated in vitro their biological activity. We injected IL-27 and IL-35-expressing lentiviral vectors into the cerebrospinal fluid (CSF) of mice affected by experimental neuroinflammation (EAE), and performed clinical, neuropathological and immunological analyses. Both cytokines interfere with neuroinflammation, but only IL-27 significantly modulates disease development, both clinically and neuropathologically. IL-27 protects from autoimmune inflammation by inhibiting granulocyte macrophages colony-stimulating factor (GM-CSF) expression in CD4+ T cells and by inducing program death-ligand 1 (PD-L1) expression in both CNS-resident and CNS-infiltrating myeloid cells. We demonstrate here that IL-27 holds therapeutic potential during neuroinflammation and that IL-27 inhibits GM-CSF and induces pd-l1 mRNA in vivo.

The selective elimination of dysfunctional mitochondria through mitophagy is crucial for preserving mitochondrial quality and cellular homeostasis. The most described mitophagy pathway is regulated by a positive ubiquitylation feedback loop in which the PINK1 (PTEN induced kinase 1) kinase phosphorylates both ubiquitin and the E3 ubiquitin ligase PRKN (Parkin RBR E3 ubiquitin ligase), also known as PARKIN. This event recruits PRKN to the mitochondria, thus amplifying ubiquitylation signal. Here we report that miR-218 targets PRKN and negatively regulates PINK1/PRKN-mediated mitophagy. Overexpression of miR-218 reduces PRKN mRNA levels, thus also reducing protein content and deregulating the E3 ubiquitin ligase action. In fact, following miR-218 overexpression, mitochondria result less ubiquitylated and the autophagy machinery fails to proceed with correct mitochondrial clearance. Since mitophagy defects are associated with various human diseases, these results qualify miR-218 as a promising therapeutic target for human diseases. &nbsp

This paper focuses on barocaloric refrigeration that could represent a practicable environmentally friendly alternative to vapor compression. The energy performances of an active barocaloric refrigerator working as a domestic cooler are evaluated by means of a 2-Dimensional model, already validated in previous investigations. The energy performances are also compared with experimental data referred to a household vapor compression refrigerator working with HFC134a. The active barocaloric regenerative refrigeration cycle is supposed to work as a domestic refrigerator in temperature range of 255 ÷ 290 K. The heat-transfer fluid is a mixture of 50%ethylene-glycol-50%water, whereas acetoxy silicone rubber is the solid-state refrigerant. In order to enhance the energy performances of the solid-state refrigerator the use of Cu-based nanofluids in the anti-freezing mixture was tested. The addition of Cu-nanoparticles to the 50%ethylene-glycol- 50%water mixture ensures a moderate enhancement of the energy performances (the maximum temperature span, cooling power and coefficient of performance enhancements are +4.0%, +7.3% and +6.7%, respectively). The analysis shows that barocaloric refrigeration can be a promising new technology in the field of domestic refrigeration for energy saving because it always overperforms vapor compression.

The notion that electrophiles serve as messengers in cell signaling is now widely accepted. Nonetheless, major issues restrain acceptance of redox homeostasis and redox signaling as components of maintenance of a normal physiological steady state. The first is that redox signaling requires sudden switching on of oxidant production and bypassing of antioxidant mechanisms rather than a continuous process that, like other signaling mechanisms, can be smoothly turned up or down. The second is the misperception that reactions in redox signaling involve “reactive oxygen species” rather than reaction of specific electrophiles with specific protein thiolates. The third is that hormesis provides protection against oxidants by increasing cellular defense or repair mechanisms rather than by specifically addressing the offset of redox homeostasis. Instead, we propose that both oxidant and antioxidant signaling are main features of redox homeostasis. As the redox shift is rapidly reversed by feedback reactions, homeostasis is maintained by continuous signaling for production and elimination of electrophiles and nucleophiles. Redox homeostasis, which is the maintenance of nucleophilic tone, accounts for a healthy physiological steady state. Electrophiles and nucleophiles are not intrinsically harmful or protective, and redox homeostasis is an essential feature of both the response to challenges and subsequent feedback. While the balance between oxidants and nucleophiles is preserved in redox homeostasis, oxidative stress provokes the establishment of a new radically altered redox steady state. The popular belief that scavenging free radicals by antioxidants has a beneficial effect is wishful thinking. We propose, instead, that continuous feedback preserves nucleophilic tone and that this is supported by redox active nutritional phytochemicals. These nonessential compounds, by activating Nrf2, mimic the effect of endogenously produced electrophiles (parahormesis). In summary, while hormesis, although globally protective, results in setting up of a new phenotype, parahormesis contributes to health by favoring maintenance of homeostasis., Graphical abstract fx1, Highlights • Redox homeostasis is the continuously challenged oxidative/nucleophilic balance. • Rheostatic redox signaling enzymes maintain oxidative/nucleophilic homeostasis. • Phytochemicals assist redox homeostasis through oxidative feedback (parahormesis). • Adaptation and hormesis while protective establish a new phenotype and set point.

This paper addresses the problem of R314a substitution with a natural refrigerant fluid. Attention is devoted to the evaluation of the environmental impact, in terms of greenhouse effect. R134a and R744 (CO2) are compared to one another. The hydrofluorocarbon R134a has a large direct warming impact (GWP), whereas the R744 contribution is negligible. The greenhouse effect is determined by the experimental evaluation of the TEWI index (Total Equivalent Warming Impact) that takes into account both direct and indirect contributions to global warming. This paper compares a commercial R134a refrigeration plant and a prototype R744 system working in a trans-critical cycle. The experimental results clearly show that the latter has a larger TEWI than the system operating with R134a. The indirect contribution to global warming provided by R744 is always greater than that of R134a. This contribution prevails in most cases. Only few operating conditions corresponding to a refrigerating plant working as a classical split system benefits, in terms of greenhouse effect, of the substitution of R134a with R744.

Cys-containing GPx8 is an intrinsic ER enzyme, whose silencing leads to H2O2 leakage. While studying GPx8 in HeLa cells, we observed that enzyme silencing deeply impacts on ER membrane lipid composition. ESI-Q-TOF-MS, integrated with principal component analysis, revealed that missing activity leads to an enrichment of neutral glycosphingolipids (GSL) and sphingomyelins (SM), but not glycerophospholipid (PL). Moreover, in all PL but phosphatidylethanonolamine, PUFA decreased. The deepest depletion of arachidonic acid was observed in phosphatidylinositol where the 18:0/18:1 replaced for up to 50% of the 18:0/20:4. Real time PCR analysis showed 30 to 50% increase of the enzymes for the ceramide (CER) biosynthesis. While expression of the CER transfer protein, involved in translocating CER from the ER to the Golgi for sphingomyelin biosynthesis, was also increased, sphingomyelin synthase 1 was not modified. This suggests that the increase of SM results from increased substrate availability due to activation of the upstream biosynthetic pathway. This evidence links the increased H2O2 efflux from ER due GPx8 silencing, and thus a more oxidizing environment, to a metabolic adaptation encompassing a modulation of specific lipid biosynthetic pathways.

Ferroptosis recapitulates the history of oxygen toxicity and lipid peroxidation. Ferroptosis is involved in degenerative diseases and is proposed as a relevant mechanism of onco-suppression. Oxygen, polyunsaturated fatty acids, iron from a labile pool, and seemingly a lipoxygenase are all required for lipid peroxidation that can only take place in the absence of GPx4 activity. Oxygen reduction unavoidably generates species competent for the formation of traces of phospholipid hydroperoxides. From these, if not immediately reduced, ferrous iron generates electrophiles alleged executing cell death. The reaction of GPx4 and the dynamics of the interaction with membranes emerge, therefore, as a crucial mechanism for the solution of the oxygen paradox. An electrostatic interaction between phospholipids and the surface of GPx4 addresses the hydroperoxide group flipping out the membrane toward the catalytic selenium of the enzyme. Catalysis of redox transition is operated by proton tunneling leading to the formation of a charge-separated species evolving barrier-less to products. Interaction of the oxidized selenium with two GSH completes the catalytic cycle and lessens the interaction with polar head of phospholipids permitting the “surfing” of the enzyme on the membrane surface.

This chapter addresses the relationship of glutathione (GSH) to Nrf2. It seems clear that there is both feedback and feed-forward signaling between Nrf2 activation and the use of GSH in protection of cells. Nrf2 activation leads to the transcription of enzymes that synthesize GSH, maintain it and NADPH in their reduced forms, and the use of GSH in protecting cells from hydroperoxides and other electrophiles. While glutathionylation of Keap1, which indicates an increase in hydroperoxide production, can signal for Nrf2 activation, GSH elimination of electrophiles and hydroperoxides decreases Nrf2 activation. These interactions contribute to redox homeostasis and, thereby, maintenance of the golden mean that defines a healthy life. Similarly, GSH is not the only nucleophile that is important in the maintenance of redox homeostasis. Other major contributing nucleophiles are NADPH, NADH, and the reduced form of thioredoxin (Trx). GSH also participates in protein folding. Protein disulfide isomerases (PDIs) and glutaredoxins (GRxs) are enzymes having a thioredoxin-like structure (thioredoxin fold).

GPx4 is a monomeric glutathione peroxidase, unique in reducing the hydroperoxide group (-OOH) of fatty acids esterified in membrane phospholipids. This reaction inhibits lipid peroxidation and accounts for enzyme's vital role. Here we investigated the interaction of GPx4 with membrane phospholipids. A cationic surface near the GPx4 catalytic center interacts with phospholipid polar heads. Accordingly, SPR analysis indicates cardiolipin as the phospholipid with maximal affinity to GPx4. Consistent with the electrostatic nature of the interaction, KCl increases the KD. Molecular dynamic (MD) simulation shows that a -OOH posed in the core of the membrane as 13 - or 9 -OOH of tetra-linoleoyl cardiolipin or 15 -OOH stearoyl-arachidonoyl-phosphaphatidylcholine moves to the lipid-water interface. Thereby, the -OOH groups are addressed toward the GPx4 redox center. In this pose, however, the catalytic site facing the membrane would be inaccessible to GSH, but the consecutive redox processes facilitate access of GSH, which further primes undocking of the enzyme, because GSH competes for the binding residues implicated in docking. During the final phase of the catalytic cycle, while GSSG is produced, GPx4 is disconnected from the membrane. The observation that GSH depletion in cells induces GPx4 translocation to the membrane, is in agreement with this concept.

A principal characteristic of redox signaling is that it involves an oxidation-reduction reaction or covalent adduct formation between the sensor signaling protein and second messenger. Non-redox signaling may involve alteration of the second messenger as in hydrolysis of GTP by G proteins, modification of the signaling protein as in farnesylation, or simple non-covalent binding of an agonist or second messenger. The chemistry of redox signaling is reviewed here. Specifically we have described how among the so-called reactive oxygen species, only hydroperoxides clearly fit the role of a second messenger. Consideration of reaction kinetics and cellular location strongly suggests that for hydroperoxides, particular protein cysteines are the targets and that the requirements for redox signaling is that these cysteines are in microenvironments in which the cysteine is ionized to the thiolate, and a proton can be donated to form a leaving group. The chemistry described here is the same as occurs in the cysteine and selenocysteine peroxidases that are generally considered the primary defense against oxidative stress. But, these same enzymes can also act as the sensors and transducer for signaling. Conditions that would allow specific signaling by peroxynitrite and superoxide are also defined. Signaling by other electrophiles, which includes lipid peroxidation products, quinones formed from polyphenols and other metabolites also involves reaction with specific protein thiolates. Again, kinetics and location are the primary determinants that provide specificity required for physiological signaling although enzymatic catalysis is not likely involved. This article is part of a Special Issue entitled "Redox Signalling in the Cardiovascular System".

Magnetic refrigeration is an emerging, environment-friendly technology based on a magnetic solid that acts as a refrigerant by magneto-caloric effect (MCE). The reference cycle for magnetic refrigeration is AMR (Active Magnetic Regenerative refrigeration). In order to demonstrate the potential of magnetic refrigeration to provide useful cooling in the near room temperature range, a novel Rotary Permanent Magnet Magnetic Refrigerator (RPMMR) is described in this paper. Gadolinium has been selected as magnetic refrigerant and demineralized water has been employed as regenerating fluid. The total mass of gadolinium (1.20 kg), shaped as packed bed spheres, is housed in 8 regenerators. A magnetic system, based on a double U configuration of permanent magnets, provides a magnetic flux density of 1.25 T with an air gap of 43 mm. A rotary vane pump forces the regenerating fluid through the regenerators. The operational principle of the magnetic refrigerator and initial experimental results are reported and analyzed.

Objectives: To develop a nomogram for estimating the glycated haemoglobin (HbA1c) response to different dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes. Design: A systematic review and meta-analysis of randomised controlled trials (RCTs) of DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, linagliptin and alogliptin) on HbA1c were conducted. Electronic searches were carried out up to December 2013. Trials were included if they were carried out on participants with type 2 diabetes, lasted at least 12 weeks, included at least 30 participants and had a final assessment of HbA1c. A random effect model was used to pool data. A nomogram was used to represent results of the metaregression model. Participants: Adults with type 2 diabetes. Interventions: Any DPP-4 inhibitor (vildagliptin, sitagliptin, saxagliptin, linagliptin or alogliptin). Outcome measures: The HbA1c response to each DPP-4 inhibitor within 1 year of therapy. Results: We screened 928 citations and reviewed 98 articles reporting 98 RCTs with 100 arms in 24 163 participants. There were 26 arms with vildagliptin, 37 with sitagliptin, 13 with saxagliptin, 13 with linagliptin and 11 with alogliptin. For all 100 arms, the mean baseline HbA1c value was 8.05% (64 mmol/mol); the decrease of HbA1c from baseline was -0.77% (95% CI -0.82 to -0.72%), with high heterogeneity (I2=96%). Multivariable metaregression model that included baseline HbA1c, type of DPP-4 inhibitor and fasting glucose explained 58% of variance between studies, with no significant interaction between them. Other factors, including age, previous diabetes drugs and duration of treatment added low predictive power (

Type 2 diabetes mellitus is a complex and progressive disease that is showing an apparently unstoppable increase worldwide. Although there is general agreement on the first-line use of metformin in most patients with type 2 diabetes, the ideal drug sequence after metformin failure is an area of increasing uncertainty. New treatment strategies target pancreatic islet dysfunction, in particular gut-derived incretin hormones. Inhibition of the enzyme dipeptidyl peptidase-4 (DPP-4) slows degradation of endogenous glucagon-like peptide-1 (GLP-1) and thereby enhances and prolongs the action of the endogenous incretin hormones. The five available DPP-4 inhibitors, also known as ‘gliptins’ (sitagliptin, vildagliptin, saxagliptin, linagliptin, alogliptin), are small molecules used orally with similar overall clinical efficacy and safety profiles in patients with type 2 diabetes. The main differences between the five gliptins on the market include: potency, target selectivity, oral bioavailability, long or short half-life, high or low binding to plasma proteins, metabolism, presence of active or inactive metabolites, excretion routes, dosage adjustment for renal and liver insufficiency, and potential drug–drug interactions. On average, treatment with gliptins is expected to produce a mean glycated hemoglobin (HbA1c) decrease of 0.5%–0.8%, with about 40% of diabetic subjects at target for the HbA1c goal

We present some additional results obtained with the BETAview system, a digital system for real time /spl beta/-imaging based on semiconductor pixel detectors and on a single photon counting read-out chip. We describe the system assembled with a Si detector, 300-/spl mu/m thick, segmented into 64 /spl times/64 square pixels with 170-/spl mu/m pitch. The solid-state pixel array detector is bump-bonded pixel by pixel to a low threshold, single particle counting electronics, the photon counting chip (PCC) developed by the Medipix1 Collaboration for biomedical applications. Each cell (corresponding to a detector pixel) of the front-end chip has a maximum count rate of 2 MHz, a minimum nominal threshold of 1400 e/sup -/ (corresponding about 5 keV in Si), and contains a 15-bit counter. The detector sensitive area is about 1 cm/sup 2/, but several detectors could be assembled in arrays. The measured background counts were about 3.5/spl times/10/sup -2/ cps/cm/sup 2/, which implies a very high sensitivity of the device. The detection threshold used in this experiment was /spl sim/15 keV. We show the results obtained in the real-time monitoring of two biological dynamic processes: an amino acid uptake by living cells and the thermal denaturation process of oligonucleotides. Specifically, we have followed over time the accumulation of a marked amino acid ([/sup 14/C]L-Leucine) into Octopus vulgaris eggs cells. The results, described in Section III-B, show that after about 20 min from the beginning of the uptake process, the radioactively marked eggs become clearly visible over the background culture radioactive medium. In Sections III-C and III-D, we also describe the successful performance of the /spl beta/-imaging system in genetic studies involving the real time reconstruction of denaturation and kinetics curves for two different /sup 32/P-radiolabeled nucleotides.

Domestic gas boilers on the market are able to modulate up to a modulation ratio equal to 10; in the present work the convenience of adopting modulation ratios up to 40 has been assessed. A methane condensing domestic boiler has been set up to work over the nominal modulation range up to 15, so that a consumption and efficiency experimental characterisation has been carried out and numerically extended to 40. A bin-method-based model has been implemented in order to estimate the modified boiler consumption for different scenarios. An increasing in the modulation ratio improves the overall boiler efficiency by reducing cycling losses yet rises the operating time and the electrical consumption; accordingly, in the present work a comprehensive analysis has been performed to identify optimal ‘ultra-modulating’ ratios for different climates and buildings.

International audience; The human genome contains 25 genes coding for selenocysteine-containing proteins (selenoproteins). These proteins are involved in a variety of functions, most notably redox homeostasis. Selenoprotein enzymes with known functions are designated according to these functions: TXNRD1, TXNRD2, and TXNRD3 (thioredoxin reductases), GPX1, GPX2, GPX3, GPX4, and GPX6 (glutathione peroxidases), DIO1, DIO2, and DIO3 (iodothyronine deiodinases), MSRB1 (methionine sulfoxide reductase B1), and SEPHS2 (selenophosphate synthetase 2). Selenoproteins without known functions have traditionally been denoted by SEL or SEP symbols. However, these symbols are sometimes ambiguous and conflict with the approved nomenclature for several other genes. Therefore, there is a need to implement a rational and coherent nomenclature system for selenoprotein-encoding genes. Our solution is to use the root symbol SELENO followed by a letter. This nomenclature applies to SELENOF (selenoprotein F, the 15-kDa selenoprotein, SEP15), SELENOH (selenoprotein H, SELH, C11orf31), SELENOI (selenoprotein I, SELI, EPT1), SELENOK (selenoprotein K, SELK), SELENOM (selenoprotein M, SELM), SELENON (selenoprotein N, SEPN1, SELN), SELENOO (selenoprotein O, SELO), SELENOP (selenoprotein P, SeP, SEPP1, SELP), SELENOS (selenoprotein S, SELS, SEPS1, VIMP), SELENOT (selenoprotein T, SELT), SELENOV (selenoprotein V, SELV), and SELENOW (selenoprotein W, SELW, SEPW1). This system, approved by the HUGO Gene Nomenclature Committee, also resolves conflicting, missing, and ambiguous designations for selenoprotein genes and is applicable to selenoproteins across vertebrates.

Objectives To evaluate glycaemic durability with dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes. Design A systematic review and meta-analysis of long-term randomised trials of DPP-4 inhibitors on haemoglobin A1c (HbA1c) was conducted. Electronic searches were carried out on the following databases: MEDLINE, EMBASE, Scopus and Web of Knowledge to December 2013. Searches were supplemented by a review of trial registries and references from identified trials. Trials were included if they lasted at least 76 weeks, and had intermediate and final assessments of HbA1c. Citations and full-text articles were screened by two reviewers. A random effect model was used to pool data. Participants Adults with type 2 diabetes. Interventions Any DPP-4 inhibitor (sitagliptin, vildagliptin, saxagliptin, linagliptin and alogliptin). Outcome measures The difference between final and intermediate HbA1c assessment was the primary outcome. Results We screened 461 citations and reviewed 12 articles reporting 12 trials in 14 829 participants. All trials were of 76 weeks duration at least. The difference in HbA1c changes between final and intermediate points averaged 0.22% (95% CI 0.15% to 0.29%), with high heterogeneity (I2=91%, p

Reversible oxidation of Cys residues is a crucial element of redox homeostasis and signaling. According to a popular concept in oxidative stress signaling, the oxidation of targets of signals can only take place following an overwhelming of the cellular antioxidant capacity. This concept, however, ignores the activation of feedback mechanisms possibly leading to a paradoxical effect. In a model of cancer stem cells (CSC), stably overexpressing the TAZ oncogene, we observed that the increased formation of oxidants is associated with a globally more reduced state of proteins. Redox proteomics revealed that several proteins, capable of undergoing reversible redox transitions, are indeed more reduced while just few are more oxidized. Among the proteins more oxidized, G6PDH emerges as both more expressed and activated by oxidation. This accounts for the observed more reduced state of the NADPH/NADP+ couple. The dynamic redox flux generating this apparently paradoxical effect is rationalized in a computational system biology model highlighting the crucial role of G6PDH activity on the rate of redox transitions eventually leading to the reduction of reversible redox switches.

Recent studies indicate carbon dioxide (R744) as a valid alternative to classical substances such as HFCs used in vapour compression plants. However a transcritical refrigeration cycle is needed because the critical temperature of carbon dioxide is usually near the ambient temperature. Consequently the carbon dioxide refrigerator performances are significantly influenced by the heat rejection pressure. In this paper an experimental investigation on working optimization for a “split-system” to cool air in residential applications is presented: by varying the heat rejection pressure an optimum working condition has been found at different ambient temperatures. Furthermore a simplified model to predict the optimum heat rejection pressure is shown and a comparison with experimental results is carried out. Both the model validation and the experimental results suggest that the heat rejection pressure optimization is an convenient method to improve the performance of a carbon dioxide split system. Finally an algorithm based on the aforementioned model has been proposed in order to control an electronic back pressure valve by means of a PLC.

Kinetics and molecular mechanisms of GPx-type enzymes are reviewed with emphasis on structural features relevant to efficiency and specificity. In Sec-GPxs the reaction takes place at a single redox centre with selenocysteine as redox-active residue (peroxidatic Sec, U(P)). In contrast, most of the non-vertebrate GPx have the U(P) replaced by a cysteine (peroxidatic Cys, C(P)) and work with a second redox centre that contains a resolving cysteine (C(R)). While the former type of enzymes is more or less specific for GSH, the latter are reduced by "redoxins". The common denominator of the GPx family is the first redox centre comprising the (seleno)cysteine, tryptophan, asparagine and glutamine. In this architectural context the rate of hydroperoxide reduction by U(P) or C(P), respectively, is enhanced by several orders of magnitude compared to that of free selenolate or thiolate. Mammalian GPx-1 dominates H(2)O(2) metabolism, whereas the domain of GPx-4 is the reduction of lipid hydroperoxides with important consequences such as counteracting 12/15-lipoxygenase-induced apoptosis and regulation of inflammatory responses. Beyond, the degenerate GSH specificity of GPx-4 allows selenylation and oxidation to disulfides of protein thiols. Heterodimer formation of yeast GPx with a transcription factor is discussed as paradigm of a redox sensing that might also be valid in vertebrates.

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a selenoperoxidase accounting for most of the selenium content in mammalian testis, which has been found to be linked to fertility in humans. In this study, we addressed the issue whether PHGPx content in spermatozoa could be a predictive index of fertilization capacity for sire selection in bulls. Measurement of PHGPx in spermatozoa of 92 yearling bulls of three different Italian breeds (Chianina, Romagnola, and Marchigiana) revealed the presence of two quite well separated populations. A PHGPx activity of 130 mU/mg separated the high-PHGPx group (H-PHGPx, n = 73) from the low-PHGPx group (L-PHGPx, n = 19). Forward motility was markedly higher in the H-PHGPx group, which also contained a lower percentage of detached heads, abnormal midpiece, and proximal droplets. On the other hand, differently from the human studies, no correlation was observed between PHGPx activity and number of spermatozoa in the ejaculate. Apart from sperm count, which typically differed among breeds, and number of detached heads in the L-PHGPx group, which correlated with higher sperm count, no other significant difference in seminal parameters among breeds was apparent. The assay for sperm PHGPx activity therefore emerges as a unique tool to evaluate semen quality for sire selection.

In this paper the experimental results of an autocascade refrigeration system for achieving ultra low temperature are presented. The plant is used to preserve tissue and cells. When the air temperature is equal to −150°C in 0.25 m3 space, the required refrigeration power is about 250 W. The influence of the most meaningful variables is discussed with regard to the design of the plant. The experimental results show an acceptable time to reach the steady state in dependence of the finality of the plant. The working substance is a non-azeotropic mixture consisting of hydrofluorocarbon (HFC) refrigerants in addition to argon and methane. Copyright © 2009 John Wiley & Sons, Ltd.