Synthesis, physico-chemical characterization and structure of the elusive hydroxylammonium lead iodide perovskite NH3OHPbI3

The elusive hydroxylammonium lead iodide NH₃OHPbI₃ has been successfully synthesized and characterized for the first time.

Efficacy and safety of switching to dolutegravir plus emtricitabine/tenofovir disoproxil fumarate (TDF) or elvitegravir/cobicistat/emtricitabine/TDF in virologically suppressed HIV-infected patients in clinical practice: results from a multicentre, observational study

OBJECTIVES

The aim of the study was to compare the efficacy and tolerability of switching antiretroviral therapy to dolutegravir + emtricitabine/tenofovir disoproxil fumarate (TDF) with those of switching to elvitegravir/cobicistat/emtricitabine/TDF in clinical practice.

METHODS

In a multicentre real-life observational study, we analysed data for HIV-infected patients on antiretroviral treatment with viral load < 50 HIV-1 RNA copies/mL switching to dolutegravir + emtricitabine/TDF (dolutegravir group) or elvitegravir/cobicistat/emtricitabine/TDF (elvitegravir group). Follow-up was censored at 48 weeks.

RESULTS

The 48-week estimated proportion maintaining virological efficacy was 96.1% with dolutegravir (n = 123) and 95.4% with elvitegravir (n = 186; P = 0.941). Patients in the dolutegravir group showed more treatment discontinuations, but these were mainly as a result of simplification. The elvitegravir group showed more discontinuations because of renal adverse events (2.7% versus 0% with dolutegravir). Interestingly, no difference was observed between the two regimens in central nervous system toxicity-related discontinuations. Switching to dolutegravir was associated with a better blood lipid profile.

CONCLUSIONS

Switching to dolutegravir + emtricitabine/TDF was associated with similar efficacy and tolerability to switching to elvitegravir/cobicistat/emtricitabine/TDF in virologically suppressed patients in clinical practice, although reasons for discontinuation showed differences between regimens. These results should be interpreted with caution, as this is a nonrandomized comparison.

Thermodynamics and the Intrinsic Stability of Lead Halide Perovskites CH3NH3PbX3

The role of thermodynamics in assessing the intrinsic instability of the CH₃NH₃PbX₃ perovskites (X = Cl,Br,I) is outlined on the basis of the available experimental information. Possible decomposition/degradation pathways driven by the inherent instability of the material are considered. The decomposition to precursors CH₃NH₃X(s) and PbX₂( s) is first analyzed, pointing out the importance of both the enthalpic and the entropic factor, the latter playing a stabilizing role making the stability higher than often asserted. For CH₃NH₃PbI₃, the disagreement between the available calorimetric results makes the stability prediction uncertain. Subsequently, the gas-releasing decomposition paths are discussed, with emphasis on the discrepant results presently available, probably reflecting the predominance of thermodynamic or kinetic control. The competition between the formation of NH₃(g) + CH₃X(g), CH₃NH₂(g) + HX(g) or CH₃NH₃X(g) is analyzed, in comparison with the thermal decomposition of methylammonium halides. In view of the scarce and inconclusive thermodynamic studies to-date available, the need for further experimental data is emphasized.

Evaluation of ATG5 polymorphisms in Italian patients with systemic lupus erythematosus: contribution to disease susceptibility and clinical phenotypes

Systemic lupus erythematosus (SLE) is a common heterogeneous autoimmune disease that is caused by the involvement both of genetic and environmental factors. There is evidence that autophagy is involved in several aspects of SLE pathogenesis. In particular, polymorphisms in the ATG5 gene have been observed to be associated with disease susceptibility. Our aim was to verify if ATG5 polymorphisms are involved in the susceptibility to disease and its clinical phenotypes in an Italian cohort of SLE patients. This study involved 315 SLE patients and 265 healthy controls. Three polymorphisms in the ATG5 gene (rs573775, rs6568431 and rs2245214) were investigated by allelic discrimination assay. A case-control association study, a genotype/phenotype correlation analysis and a haplotype study were performed. Moreover, an expression study was conducted in peripheral blood mononuclear cells from 15 SLE patients to verify a possible effect of the three SNPs on the expression of ATG5. Among the three investigated SNPs, only the rs573775 SNP was significantly associated with disease susceptibility with the variant allele conferring a higher risk of developing SLE (OR = 1.50, p = 0.018 and OR = 1.48, p = 0.007 at the genotypic and allelic level, respectively). The variant allele of rs6568431 SNP was more present in patients with anemia (OR = 1.86, p = 0.009) and renal involvement (OR = 1.63, p = 0.06), while the variant allele of rs2245214 SNP was significantly associated with a higher risk of producing anti-DNA autoantibodies (OR = 1.66, p = 0.04). Carriers of the rs6568431 variant allele showed higher messenger RNA levels compared to the carriers of the wild-type allele, suggesting also a potential variant allele dose-dependent effect on gene expression. In conclusion, our study confirms a role for ATG5 polymorphisms both in disease susceptibility and in the modulation of clinical phenotypes in an Italian SLE cohort. These results further suggest that genetic variations in autophagy genes could play a role in autoimmune diseases susceptibility and are worth further investigation.

Efficacy and tolerability of lamivudine plus dolutegravir as a switch strategy in a multicentre cohort of patients with suppressed HIV-1 replication

OBJECTIVES

We evaluated the efficacy and tolerability of lamivudine + dolutegravir in a cohort of HIV-1 infected, treatment-experienced patients with undetectable HIV-RNA.

METHODS

Time to treatment discontinuation (TD) and virological failure (VF) and their predictors were assessed in a multicenter cohort of HIV-1 infected patients, starting lamivudine + dolutegravir after reaching viral suppression. Secondary objective was the evaluation of changes in lipid profile, renal and immunological functions at week 48.

RESULTS

We enrolled 206 patients (72.8% male, with 51 years median age), who mainly switched their antiretroviral therapy for simplification (32.5%) or drug toxicity (54.5%). The estimated probability of maintaining virological suppression at 48 and 96 weeks was 98.2% and 95.1%, respectively. VF was independently predicted by cumulative time on antiretroviral therapy. The estimated probability of remaining on lamivudine plus dolutegravir was 86.7% and 80.5% at week 48 and 96, respectively. A significant improvement in immunological function (CD4 count and CD4/CD8 ratio) was evidenced at week 48, as well as a decrease in total cholesterol/HDL ratio, triglycerides and estimated glomerular filtration rate.

CONCLUSIONS

Lamivudine plus dolutegravir was effective in maintaining viral suppression in our cohort and led to an improvement in metabolic and immunologic functions.

Structural modification of titanium surface by octacalcium phosphate via Pulsed Laser Deposition and chemical treatment

In the present study, the Pulsed Laser Deposition (PLD) technique was applied to coat titanium for orthopaedic and dental implant applications. Calcium carbonate (CC) was used as starting coating material. The deposited CC films were transformed into octacalcium phosphate (OCP) by chemical treatments. The results of X-ray diffraction (XRD), Raman, Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM) studies revealed that the final OCP thin films are formed on the titanium surface. Human myofibroblasts from peripheral vessels and the primary bone marrow mesenchymal stromal cells (BMMSs) were cultured on the investigated materials. It was shown that all the investigated samples had no short-term toxic effects on cells. The rate of division of myofibroblast cells growing on the surface and saturated BMMSs concentration for the OCP coating were about two times faster than of cells growing on the CC films.

A polymorphism upstream MIR1279 gene is associated with pericarditis development in Systemic Lupus Erythematosus and contributes to definition of a genetic risk profile for this complication

Recently, a study has shown that a polymorphism in the region of MIR1279 modulates the expression of the TRAF3IP2 gene. Since polymorphisms in the TRAF3IP2 gene have been described in association with systemic lupus erithematosus (SLE) susceptibility and with the development of pericarditis, our aim is to verify if the MIR1279 gene variability could also be involved. The rs1463335 SNP, located upstream MIR1279 gene, was analyzed by allelic discrimination assay in 315 Italian SLE patients and 201 healthy controls. Moreover, the MIR1279 gene was full sequenced in 50 patients. A case/control association study and a genotype/phenotype correlation analysis were performed. We also constructed a pericarditis genetic risk profile for patients with SLE. The full sequencing of the MIR1279 gene in patients with SLE did not reveal any novel or known variation. The variant allele of the rs1463335 SNP was significantly associated with susceptibility to pericarditis ( P = 0.017 and OR = 1.67). A risk profile model for pericarditis considering the risk alleles of MIR1279 and three other genes (STAT4, PTPN2 and TRAF3IP2) showed that patients with 4 or 5 risk alleles have a higher risk of developing pericarditis ( OR = 4.09 with P = 0.001 and OR = 6.04 with P = 0.04 respectively). In conclusion, we describe for the first time the contribution of a MIR1279 SNP in pericarditis development in patients with SLE and a genetic risk profile model that could be useful to identify patients more susceptible to developing pericarditis in SLE. This approach could help to improve the prediction and the management of this complication.

In-vacuum thermolysis of ethane 1,2-diamineborane for the synthesis of ternary borocarbonitrides

High-temperature (1000 °C) thermolytic decomposition of ethane 1,2-diamineborane (BH3NH2CH2CH2NH2BH3) deposited onto a Cu foil has been performed in an ultra-high-vacuum environment. A combined thermolytic, structural (x-ray diffraction), microscopic (scanning electron microscopy) and spectroscopic (Raman, x-ray photoemission spectroscopy) analysis, has identified a ternary borocarbonitride (BCN) compound as a result of the process. The obtained BCN compound is nanocrystalline, surrounded by crystallites of ammonium hydroxide borate hydrate. The ternary compound presents a 0.2:0.6:0.2 B:C:N composition in the bulk and 0.11:0.76:0.13 stoichiometry at the very surface, richer in C-C networks with respect to the bulk. Furthermore, the resulting BCN compound does not show oxidation at the surface due to the in-vacuum thermolysis of the single precursor.

On the Thermal and Thermodynamic (In)Stability of Methylammonium Lead Halide Perovskites

The interest of the scientific community on methylammonium lead halide perovskites (MAPbX3, X = Cl, Br, I) for hybrid organic-inorganic solar cells has grown exponentially since the first report in 2009. This fact is clearly justified by the very high efficiencies attainable (reaching 20% in lab scale devices) at a fraction of the cost of conventional photovoltaics. However, many problems must be solved before a market introduction of these devices can be envisaged. Perhaps the most important to be addressed is the lack of information regarding the thermal and thermodynamic stability of the materials towards decomposition, which are intrinsic properties of them and which can seriously limit or even exclude their use in real devices. In this work we present and discuss the results we obtained using non-ambient X-ray diffraction, Knudsen effusion-mass spectrometry (KEMS) and Knudsen effusion mass loss (KEML) techniques on MAPbCl3, MAPbBr3 and MAPbI3. The measurements demonstrate that all the materials decompose to the corresponding solid lead (II) halide and gaseous methylamine and hydrogen halide, and the decomposition is well detectable even at moderate temperatures (~60 °C). Our results suggest that these materials may be problematic for long term operation of solar devices.

Reduced risk of Efavirenz Discontinuation in Naïve Patients Starting First-Line Antiretroviral Therapy with Single Tablet versus dual Tablet Regimen

OBJECTIVES

Despite not being approved in Europe as first-line therapy, the efavirenz (EFV)-containing single tablet regimen (STR) is frequently used in clinical practice in naïve patients but few data are available on this strategy. In our study, we aimed to assess the risk of EFV discontinuation in patients starting antiretroviral therapy with STR vs. nonSTR.

METHODS

This was a multicentre study retrospectively enrolling naïve patients starting EFV+TDF+FTC. Patients were followed from the time of treatment initiation to the discontinuation of the EFV-containing regimen, comparing STR vs. nonSTR. Two different analyses were performed: (A) nonSTR patients censored at the last observation (switch to STR not considered as the end of observation); (B) nonSTR patients censored at the time of switch to STR.

RESULTS

The study included 235 patients, of whom 74 (31.5%) directly started STR. Among patients starting nonSTR, 108 (67.1%) switched to STR after a median period of 6 months. Forty-four EFV discontinuations were observed (13 among STR vs. 31 among nonSTR patients). The overall estimated probability of discontinuation was 30% at 5 years, about half (14.8%) of these occurring during the first year. Analysis A did not show significant differences between STR and nonSTR regarding the probability of efavirenz discontinuation (19.9% vs. 24.7% at 5 years, P = 0.630). In contrast, Analysis B showed that the probability of EFV discontinuation was similar (8.3%) between STR and nonSTR patients up to 8 months. Thereafter, a significantly higher rate of discontinuation was observed in nonSTR patients (47.5% vs. 19.9% at 5 years, P = 0.034).

CONCLUSIONS

Our data suggest that an early switch to STR during the first months of treatment could reduce the risk of EFV discontinuation.

HIV-1 integrase genotyping is reliable and reproducible for routine clinical detection of integrase resistance mutations even in patients with low-level viraemia

OBJECTIVES

Integrase drug resistance monitoring deserves attention because of the increasing number of patients being treated with integrase strand-transfer inhibitors. Therefore, we evaluated the integrase genotyping success rate at low-level viraemia (LLV, 51-1000 copies/mL) and resistance in raltegravir-failing patients.

METHODS

An integrase genotypic resistance test (GRT) was performed on 1734 HIV-1 samples collected during 2006-13. Genotyping success rate was determined according to the following viraemia levels: 51-500, 501-1000, 1001-10 000, 10 001-100 000 and >100 000 copies/mL. The reproducibility of integrase GRT was evaluated in 41 plasma samples processed in duplicate in two reference centres. The relationship between LLV and resistance prevalence was evaluated in a subset of 120 raltegravir-failing patients.

RESULTS

Overall, the integrase genotyping success rate was 95.7%. For viraemia levels 51-500 and 501-1000 copies/mL, the rate of success was 82.1% and 94.0%, respectively. GRT was reproducible, producing sequences with a high similarity and an equal resistance profile regardless of the sequencing centre or viraemia level. Resistance was detected both at LLV and at viraemia >1000 copies/mL (51-500 copies/mL = 18.2%; 501-1000 = 37.5%; 1001-10 000 = 53.7%; 10 001-100 000 = 30.0%; and >100 000 = 30.8%). At viraemia ≤500 copies/mL, Q148H/K/R and N155H had the same prevalence (9.1%), while the Y143C/H/R was completely absent. At early genotyping (within 3 months of raltegravir treatment), Q148H/K/R and N155H mutations were detected regardless of the viraemia level, while Y143C/H/R was observed only in samples with viraemia >1000 copies/mL.

CONCLUSIONS

Our findings prove the reliability of HIV-1 integrase genotyping and reinforce the concept that this assay may be useful in the management of failures even at LLV.

Bioactive, nanostructured Si-substituted hydroxyapatite coatings on titanium prepared by pulsed laser deposition

AIMS

The aim of this work was to deposit silicon-substituted hydroxyapatite (Si-HAp) coatings on titanium for biomedical applications, since it is known that Si-HAp is able to promote osteoblastic cells activity, resulting in the enhanced bone ingrowth.

MATERIALS AND METHODS

Pulsed laser deposition (PLD) method was used for coatings preparation. For depositions, Si-HAp targets (1.4 wt % of Si), made up from nanopowders synthesized by wet method, were used.

RESULTS

Microstructural and mechanical properties of the produced coatings, as a function of substrate temperature, were investigated by scanning electron and atomic force microscopies, X-ray diffraction, Fourier transform infrared spectroscopy, and Vickers microhardness. In the temperature range of 400-600°C, 1.4-1.5 µm thick Si-HAp films, presenting composition similar to that of the used target, were deposited. The prepared coatings were dense, crystalline, and nanostructured, characterized by nanotopography of surface and enhanced hardness. Whereas the substrate temperature of 750°C was too high and led to the HAp decomposition. Moreover, the bioactivity of coatings was evaluated by in vitro tests in an osteoblastic/osteoclastic culture medium (α-Modified Eagle's Medium).

CONCLUSIONS

The prepared bioactive Si-HAp coatings could be considered for applications in orthopedics and dentistry to improve the osteointegration of bone implants.

Continuous increase in HIV-1 incidence after the year 2000 among men who have sex with men in Rome: insights from a 25-year retrospective cohort study

To assess trends in HIV-1 incidence and risk factors for seroconversion among men who have sex with men (MSM) resident in Rome, Italy, a retrospective longitudinal cohort study was conducted over 25 years. Incidence rates and trends were modelled using Poisson regression and risk factors were assessed by multivariate Cox models. Of 1,862 HIV-1-negative individuals, 347 seroconverted during follow-up. HIV-1 incidence rates increased from 5.2/100 persons/year (p/y) in 1986 (95% confidence interval (CI): 2.3–11.5) to 9.2/00 p/y in 1992 (95% CI: 6.4–13.0), decreased to 1.3/100 p/y in 2001 and increased until 2009 (11.7/100 p/y; 95% CI: 7.4–18.6). The risk of HIV-1 seroconversion increased during the study period in younger MSM (incidence rate ratio (IRR) = 17.18; 95% CI: 9.74–30.32 in 16–32 year-olds and IRR = 5.09; 95% CI: 2.92–8.87 in 33–41 year-olds) and in those who acquired syphilis (IRR = 7.71; 95% CI: 5.00–11.88). In contrast, the risk of seroconversion decreased among highly educated MSM (IRR = 0.54; 95% CI: 0.35–0.82) and those without Italian citizenship (IRR = 0.45; 95% CI: 0.28–0.71). The HIV epidemic in MSM living in Rome continues to expand. Targeted prevention programmes against sexually transmitted infections to enhance knowledge transfer and behavioural skills are urgently required.

Acoustic radiation force impulse (ARFI) imaging with Virtual Touch Tissue Quantification in liver disease associated with cystic fibrosis in children

PURPOSE

Cystic-fibrosis-associated liver disease (CFLD) may lead to portal hypertension (PHT) and cirrhosis. Clinical signs and biochemistry of liver involvement are not discriminating. The aim of the study was to evaluate the performance of acoustic radiation force impulse (ARFI) with virtual tissue quantification in comparison with clinical signs, biochemistry and standard hepatic ultrasound (US) patterns.

MATERIALS AND METHODS

Virtual Touch Tissue Quantification, an implementation of US ARFI with shear-wave velocity (SWV) measurements was used in 75 children with cystic fibrosis (CF) and suspected CFLD to quantify hepatic stiffness. In each patient, ten measurements of SWV were performed on the right hepatic lobe. Patients were also evaluated by standard diagnostic tools (standard US, liver- and lung function tests, oesophagogastroscopy).

RESULTS

Among CF patients, median SWV was significantly higher in patients with clinical, biochemical and US signs of hepatic involvement than in patients without US evidence of liver disease 1.08 m/s [(95% confidence interval (CI), 1.02-1.14]. Median SWV values in patients with portal hypertension, splenomegaly and oesophageal varices were 1.30 (95% CI, 1.17-1.43), 1.54 (95% CI, 1.32-1.75) and 1.63 (95% CI, 1.26-1.99), respectively. Differences were significant (p<0.001).

CONCLUSIONS

ARFI is an innovative screening technique able to help identify CFLD in children.