Hardware Implementation of Quantum Stabilizers in Superconducting Circuits.

Stabilizer operations are at the heart of quantum error correction and are typically implemented in software-controlled entangling gates and measurements of groups of qubits. Alternatively, qubits can be designed so that the Hamiltonian corresponds directly to a stabilizer for protecting quantum information. We demonstrate such a hardware implementation of stabilizers in a superconducting circuit composed of chains of π-periodic Josephson elements. With local on-chip flux and charge biasing, we observe a progressive softening of the energy band dispersion with respect to flux as the number of frustrated plaquette elements is increased, in close agreement with our numerical modeling.

Species diversity and mycotoxin production by members of the Fusarium tricinctum species complex associated with Fusarium head blight of wheat and barley in Italy.

Fusarium head blight (FHB) is a global cereal disease caused by a complex of Fusarium species. In Europe, the main species responsible for FHB are F. graminearum, F. culmorum and F. poae. However, members of the F. tricinctum species complex (FTSC) have become increasingly important. FTSC fusaria can synthesize mycotoxins such as moniliformin (MON), enniatins (ENNs) and several other biologically active secondary metabolites that could compromise food quality. In this study, FTSC isolates primarily from Italian durum wheat and barley, together with individual strains from four non-graminaceous hosts, were collected to assess their genetic diversity and determine their potential to produce mycotoxins in vitro on rice cultures. A multilocus DNA sequence dataset (TEF1, RPB1 and RPB2) was constructed for 117 isolates from Italy and 6 from Iran to evaluate FTSC species diversity and their evolutionary relationships. Phylogenetic analyses revealed wide genetic diversity among Italian FTSC isolates. Among previously described FTSC species, F. avenaceum (FTSC 4) was the most common species in Italy (56/117 = 47.9%) while F. tricinctum (FTSC 3), and F. acuminatum (FTSC 2) accounted for 11.1% (13/117) and the 8.5% (10/117), respectively. The second most detected species was a new and unnamed Fusarium sp. (FTSC 12; 32/117 = 19%) resolved as the sister group of F. tricinctum. Collectively, these four phylospecies accounted for 111/117 = 94.9% of the Italian FTSC collection. However, we identified five other FTSC species at low frequencies, including F. iranicum (FTSC 6) and three newly discovered species (Fusarium spp. FTSC 13, 14, 15). Of the 59 FTSC isolates tested for mycotoxin production on rice cultures, 54 and 55 strains, respectively, were able to produce detectable levels of ENNs and MON. In addition, we confirmed that the ability to produce bioactive secondary metabolites such as chlamydosporol, acuminatopyrone, longiborneol, fungerin and butanolide is widespread across the FTSC.

Flexural strength and elastic modulus evaluation of structures made by conventional PMMA and PMMA reinforced with graphene.

OBJECTIVE: The aim of this study was to compare both the elastic modulus (EM) and the flexural strength (FS) of two materials used in dental prosthesis, namely polymethylmethacrylate (PMMA) and polymethylmethacrylate reinforced with graphene (G-PMMA). MATERIALS AND METHODS: Twenty rectangular samples were manufactured by a milling machine and divided into two groups (n= 10/group): Group 1, PMMA; Group 2, G-PMMA. The specimens were subjected to a three-point bending test conducted in the elastic range to evaluate EM. A similar test was protracted until fracture to evaluate FS. Data on EM and FS were statistically analyzed with independent-samples t-test in order to compare the two groups. A scanning electron microscope (SEM) (5.00 kx and 1.00 kx magnification) was used to evaluate the morphology of sample's fracture. RESULTS: Compared to PMMA samples, each G-PMMA sample showed significantly higher values of FS (p <0.001) and EM (p <0.001). SEM images analysis showed an inhomogeneous fracture morphology in G-PMMA samples. CONCLUSIONS: The results show that G-PMMA is a promising material to be used for prosthetic purposes. This is demonstrated by a significant increase in both peak load and bending stiffness, resulting from the bending test performed on G-PMMA samples. Furthermore, the latter exhibit greater homogeneity in their mechanical behavior, supporting the potential value of this material in dental prosthesis.

Causal agents of Fusarium head blight of durum wheat (Triticum durum Desf.) in central Italy and their in vitro biosynthesis of secondary metabolites.

Durum wheat samples harvested in central Italy (Umbria) were analyzed to: evaluate the occurrence of the fungal community in the grains, molecularly identify the Fusarium spp. which are part of the Fusarium head blight (FHB) complex and characterize the in vitro secondary metabolite profiles of a subset of Fusarium strains. The Fusarium genus was one of the main components of the durum wheat fungal community. The FHB complex was composed of eight species: Fusarium avenaceum (61%), F. graminearum (22%), F. poae (9%), F. culmorum (4%), F. proliferatum (2%), F. sporotrichioides (1%), F. sambucinum (0.5%) and F. langsethiae (0.5%). F. graminearum population was mainly composed of the 15-acetyldeoxynivalenol chemotype, while, F. culmorum population was composed of the 3-acetyldeoxynivalenol chemotype. In vitro characterization of secondary metabolite biosynthesis was conducted for a wide spectrum of substances, showing the mycotoxigenic potential of the species complex. F. avenaceum strains were characterized by high enniantin and moniliformin production. F. graminearum strains were in prevalence deoxynivalenol producers. F. poae strains were characterized by a high biosynthesis of beauvericin like the F. sporotrichioides strain which was also found to be a high T-2/HT-2 toxins producer. Production of aurofusarin, butenolide, gibepyrone D, fusarin C, apicidin was also reported for the analyzed strains.

Proteinuria is a predictor of posttransplant anemia.

INTRODUCTION: Posttransplant anemia (PTA) involves many factors. Although the link between the hemoglobin (Hb) levels and renal function is known, the relationship between proteinuria and PTA hemoglobin has not been widely explored. The aim of this study was to evaluate whether proteinuria was a predictor of anemia and whether erythropoietin-stimulating agent therapy was a protective factor for kidney damage among transplantation patients. METHODS: We retrospectively examined 144 kidney transplant recipients of mean age 44.4 ± 12.3 years and a mean follow-up period of 40.5 ± 4.6 months. Exclusion criteria were age under 18 years, multiorgan transplantation, proteinuria at 6 months over 1.5 g/d, and transplant failure within the first year. Using regression models, we evaluated the potential predictive power of proteinuria at 6 months after renal transplantation for anemia as expressed by Hb levels at 1 year. RESULTS: The frequency of patients with PTA was 38.89% at 1 year, 35.21% at 2 years, and 31.43% at 3 years. Variables with significant correlations with anemia upon univariate analysis were: proteinuria, donor age, acute rejection, estimated glomerular filtration rate, s-creatinine, and salbumin. Upon multivariate regression analysis 24-hour proteinuria and s-albumin remained independent predictors of 1-year PTA. Univariate analysis among the entire cohort showed a significant correlation between 1-year Hb and proteinuria/24 hours at 6 months (P=.007), an observation that was confirmed in the adjusted model along with recipient sex. Patients were then divided into two groups regarding treatment with erythropoiesis stimulating agents (ESA). Multivariate analysis showed that proteinuria (P=.005) was a predictor of Hb only among the group of patients who did no receive erythropoietin, whereas this relationship disappeared among the group treated with ESA. CONCLUSIONS: These results showed that proteinuria at 6 months was a predictor of Hb levels at 1 year. Treatment of transplant patients with ESA may be a protective factor for renal endothelial damage expressed as proteinuria.

Pulmonary hypertension and erythropoietin.

Numerous uremic patients on hemodialysis have pulmonary hypertension attributable to the presence of arteriovenous fistulas, vascular calcification, and endothelial dysfunction due to alterations in the balance between vasoconstrictive and vasodilatory substances. For these reasons, the effects of recombinant human erythropoietin, a drug widely used in patients on dialysis, on the pulmonary circulation were studied. Some authors maintain that recombinant human erythropoietin has an antihypertensive effect, while others have observed that this hormone induces a reduction in pulmonary arterial pressure due to its vasoactive and stimulatory effects on endothelial and smooth muscle cell precursors.

[Respiratory function abnormalities in uremic patients]. / Alterazioni della funzionalità respiratoria nel paziente uremico.

Patients with end-stage renal disease treated by hemodialysis are exposed to continuous pulmonary insults of multifactorial origin. Alterations in respiratory drive, mechanics, muscle function and gas exchange are frequent in hemodialysis patients. Pulmonary dysfunction may be the direct consequence of circulating uraemic toxins or may result indirectly from volume overload, anaemia, immune suppression, extraosseous calcification, malnutrition, electrolyte disorders, and/or acid-base imbalances. We have emphasised how derangement of diffusing capacity represents the most frequent and important respiratory abnormality in haemodialysed patients. It has been postulated that some forms of selective damage in the alveolo-capillary wall interferes with alveolar gas exchange.

[Isolated peripheral arterial ischaemia and medullary neurostimulation: case report]. / Ischemia arteriosa periferica isolata e neurostimolazione midollare: case report.

Isolated peripheral arterial ischaemia (IPAI) is an unusual pathology of dialysis and peritoneal patients which represents the first sign of a complication of uraemia known as calciphylaxis. Recent studies have revealed an increased incidence of this complication. Risk factors are known but there is no consensus on them: elevated CaxP product, female gender, elevated serum parathormone. We present here the case of a 65-year-old man with 21-year history of dialysis, distal isolated ulceration and without any signs of severe vasculopathy. Our clinical diagnosis was calciphylaxis. In this case, the role of early PTX is not clear and the use of steroids is recommended only in non-ulcerating cases. The therapy gives good results but not in all patients. Electrical stimulation of the posterior roots of the spinal cord is an alternative approach to this case. We hypothesised that the electrical action, through cutaneous vasodilatation of afferent dorsal fibres and release of calcitonin gene-releasing protein, determines the release of prostaglandin E sub 2 that may positively affect the proliferation and activity of epidermal fibroblasts.

Effects of homocysteine on proliferation, necrosis, and apoptosis of vascular smooth muscle cells in culture and influence of folic acid.

BACKGROUND: It is known that hyperhomocysteinemia is associated with an increased risk of vascular disease, yet little is known about the pathogenic mechanisms underlying the action of homocysteine (Hcy) itself. METHODS: We evaluated the effects of Hcy on cell proliferation, apoptosis, and necrosis in smooth muscle cells (SMCs) cultured for 24 h with different amounts of Hcy. The percentage of apoptotic and necrotic cells from the culture was evaluated using two different techniques: annexin V-FITC and propidium iodide (PI) fluorescence and apoptosis TUNEL assay. RESULTS: The addition of 10 microM/l of Hcy to the medium was followed by a significant increase in cell proliferation and death, through apoptosis and necrosis, respectively. Notwithstanding this apparent balance, a significant increase was found in the total number of cells present in Hcy-treated culture, thus demonstrating a positive dose-dependent correlation with Hcy concentrations in the culture medium. The addition of folic acid to the culture medium significantly reduced both Hcy concentrations in media and the effects of Hcy on the proliferation/apoptosis/necrosis balance of cells in culture. The percentages for apoptotic cells and for cells with a necrotic morphology continued to increase as Hcy concentrations increased, although the absolute values were lower in the culture treated than in that not treated with folic acid. CONCLUSIONS: In the presence of folic acid, at increasing concentrations of Hcy, the total number of cells in culture showed increases far less relevant with respect to the control. Also the percentage of apoptotic cells to that of cells with a necrotic morphology, although conserving the tendency to increase to growth of the concentrations of Hcy, have shown absolute values that were lower in the folic acid-treated cultures.

Cell proliferation/cell death balance in renal cell cultures after exposure to a static magnetic field.

The effect of a static magnetic field (MF) of 0.5 mT of intensity on the cell proliferation/cell death balance was investigated in renal cells (VERO) and cortical astrocyte cultures from rats. Magnetic stimulation was delivered by magnetic disks at known intensities. The percentage of apoptotic and necrotic cells was evaluated using flow cytometry and morphological analysis following Hoechst chromatin staining. An index of cell proliferation was determined using sulfonated tetrazolium (WST-1). Control cultures were prepared without exposure to MFs. After 2, 4 and 6 days of exposure to a MF, we observed a gradual decrease in apoptosis and proliferation and a gradual increase in cells with a necrotic morphology with respect to the control group. In astrocyte cultures, over a 6-day exposure period. A gradual increase was observed in apoptotic, proliferating, and necrotic cells. Our findings suggest that the effect of exposure to MFs varies, depending on the cell type; MFs may also have a nephropathogenic effect.

Cardiovascular remodeling, apoptosis, and drugs.

Apoptosis, a form of programmed cell death, mediates the controlled deletion of so-called "unwanted" cells. This review deals with the key features of this cell death program, showing that apoptosis is regulated by factors extrinsic and intrinsic to the dying cell. The elucidation of the possible interactions between these factors may be of major interest in preventing the progression to cardiovascular remodeling in patients with hypertensive disease. New pathways of research are emerging for drugs, such as beta-blockers, ACE inhibitors, the calcium-antagonists, and the receptor antagonist of angiotensin II, all of which have beneficial effects on cardiovascular remodeling. This may be due to the direct effect of these drugs on the cell proliferation/apoptosis balance.

Effect of fluvastatin on proteinuria in patients with immunoglobulin A nephropathy.

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are established drugs for the treatment of hypercholesterolemia, but several studies have shown that benefits obtained with these drugs are not causally related only to regression of cholesterol lowering. Moreover, in experimental models of progressive renal disease, statins have reduced the extent of glomerulosclerosis. This study evaluated the antiproteinuric effect of a daily dose of 40 mg fluvastatin for 6 months in moderately proteinuric patients with immunoglobulin A nephropathy, stable renal function, and no indicators of poor long-term prognosis. The effects of therapy were evaluated on the basis of 24-hour proteinuria (total proteinuria and albuminuria), albuminemia, creatinine clearance, cholesterol, and triglyceride values. Renal function remained stable in all patients. A significant decrease in proteinuria was observed after 6 months of therapy and persisted for all the observations. An increase in serum albumin was observed after 6 months of therapy. This study suggests that there is an antiproteinuric effect of HMG-CoA reductase inhibitors in moderately proteinuric patients with immunoglobulin A nephropathy.

Water immersion increases urinary excretion of aquaporin-2 in healthy humans.

Many previous studies have shown that aquaporin-2 (AQP2), the vasopressin-regulated water channel, is excreted in the urine and that the excretion increases in response to vasopressin. Moreover, recently a close correlation between AQP2 excretion in urine and kidney AQP2 expression has been demonstrated, showing that urinary excretion of AQP2 is a reliable indicator for AQP-2 function. As head-out water immersion causes an expansion in the central vascular volume equal to that induced by 2 liters of saline, without modifying plasma composition, we used immersion in water to evaluate if the response to acute expansion of the central vascular volume could involve vasporessin (AVP) and AQP2. In healthy subjects, concentrations of plasma atrial natriuretic factor (ANF) and AVP, and urinary AQP2 were measured during a 2-hour immersion period. In all subjects, immersion caused a prompt and marked increase in immunoreactive ANF (23.0 +/- 2.12 pg/ml at second hour vs. 2.17 +/- 0.42 pg/ml at baseline) and in urinary excretion of AQP2 (23.9 +/- 2. 69 pmol/mg creatinine at second hour vs. 4.42 +/- 0.14 pmol/mg creatinine at baseline), while a significant decrease was found in plasma AVP. Recovery was associated with a prompt return to pre-study levels. These findings demonstrate that heat-out water immersion stimulates urinary excretion of AQP2 in absence of an increase in plasma AVP.

Pro-apoptotic effect of fluvastatin on human smooth muscle cells.

The antiatherosclerotic effect of statins has been attributed to their hypocholesterolemic action. We therefore evaluated the effect, in vitro, of the addition of the serum of patients taking fluvastatin on human smooth muscle cells in order to ascertain the effect of the drug on cell proliferation and apoptosis. We found that the addition of serum from patients treated with fluvastatin for 6 days caused a significant reduction in cell proliferation, increased cell apoptosis and reduced the B cell leukemia-2 (bcl-2) concentration. It is concluded that the induction of apoptosis by statins could be a supplementary mechanism in the prevention of atherosclerotic lesions in humans.

Reduced bcl-2 concentrations in hypertensive patients after lisinopril or nifedipine administration.

In 30 patients with essential hypertension and 30 healthy control subjects, we evaluated blood concentrations of B cell leukemia-2 (bcl-2), a protooncogene that can reduce apoptosis. Bcl-2 concentrations were higher in hypertensive than in normotensive subjects. The increase in pressure due to a cold pressor test caused a further increase in blood bcl-2 concentrations, in both hypertensive and normotensive subjects. Treatment of hypertensive patients with hypotensive drugs caused a reduction in bcl-2 concentrations, which was more marked after administration of lisinopril than of nifedipine. The results suggest that concentrations of bcl-2 are increased in patients with hypertension, which could be an important factor in cell proliferation underlying posthypertensive vascular remodeling. Moreover, lisinopril and nifedipine appear to be capable of reducing bcl-2 concentrations, with potentially beneficial effects on vascular modifications in patients with hypertension.