Microscopic dynamics of gas molecules confined in porous channel-like ice structure.

In the rich ice polymorphism landscape, ice XVII, metastable at ambient pressure and at temperatures below 130 K, is surely one of the most interesting from both fundamental and technological perspectives due to its porosity, i.e., its capability to repeatedly absorb and desorb molecular hydrogen by dosing the gas at pressures even below the ambient one. Here, owing to this exceptional key feature, we investigate the roto-vibrational dynamics of the H2 molecules trapped in the fully deuterated ice XVII structure. Making use of the high-resolution and brilliance of the TOSCA neutron vibrational spectrometer, combined with high-resolution Raman data, we are able to efficiently distinguish the center-of-mass translational bands from the rotational ones and to study them as a function of the guest filling of the ice structure, unraveling a peculiar behavior for the confined particle in a low-dimensional system. Moreover, we also report the study of the microscopic dynamics of confined nitrogen and oxygen, which are the most abundant molecular species in the atmosphere and are of paramount interest for technological applications. Finally, we show that the ice XVII porosity is a unique feature, especially in the low pressure regime, within the emptied-hydrate phases discovered to date.

Pathophysiology of respiratory failure in patients with osteogenesis imperfecta: a systematic review.

INTRODUCTION: Respiratory failure is a major cause of death in patients with Osteogenesis Imperfecta. Moreover, respiratory symptoms seem to have a dramatic impact on their quality of life. It has long been thought that lung function disorders in OI are mainly due to changes in the thoracic wall, caused by bone deformities. However, recent studies indicate that alterations in the lung itself can also undermine respiratory health. OBJECTIVES: Is there any intrapulmonary alteration in Osteogenesis Imperfecta that can explain decreased pulmonary function? The aim of this systematic literature review is to investigate to what extent intrapulmonary or extrapulmonary thoracic changes contribute to respiratory dysfunction in Osteogenesis Imperfecta. METHODS: A literature search (in PubMed, Embase, Web of Science, and Cochrane), which included articles from inception to December 2020, was performed in accordance with the PRISMA guidelines. RESULTS: Pulmonary function disorders have been described in many studies as secondary to scoliosis or to thoracic skeletal deformities. The findings of this systematic review suggest that reduced pulmonary function can also be caused by a primary pulmonary problem due to intrinsic collagen alterations. CONCLUSIONS: Based on the most recent studies, the review indicates that pulmonary defects may be a consequence of abnormal collagen type I distorting the intrapulmonary structure of the lung. Lung function deteriorates further when intrapulmonary defects are combined with severe thoracic abnormalities. This systematic review reveals novel findings of the underlying pathological mechanism which have clinical and diagnostic implications for the assessment and treatment of pulmonary function disorders in Osteogenesis Imperfecta.KEY MESSAGESDecreased pulmonary function in Osteogenesis Imperfecta can be attributed to primary pulmonary defects due to intrapulmonary collagen alterations and not solely to secondary problems arising from thoracic skeletal dysplasia.Type I collagen defects play a crucial role in the development of the lung parenchyma and defects, therefore, affect pulmonary function. More awareness is needed among physicians about pulmonary complications in Osteogenesis Imperfecta to develop novel concepts on clinical and diagnostic assessment of pulmonary functional disorders.

Vertebral fracture assessment (VFA) for monitoring vertebral reshaping in children and adolescents with osteogenesis imperfecta treated with intravenous neridronate.

PURPOSE: The study was aimed at monitoring vertebral bodies changes with the use of Vertebral Fracture Assessment (VFA) in children and adolescents affected by osteogenesis imperfecta (OI) during treatment with intravenous neridronate. METHODS: 60 children and adolescents (35 males and 25 females; age 1-16 years) with OI type I, III and IV were included in the study. Intravenous neridronate was administered at the dose of 2 mg/kg every 3 months in all patients. Lumbar spine (LS) bone mineral density (BMD) and VFA by dual X-ray absorptiometry (DXA) were assessed every 6 months up to 24 months during treatment. VFA with vertebral morphometry (MXA) was used to calculate the three indices of vertebral deformity: wedging, concavity and crushing. Serum calcium, phosphate, parathyroid hormone (PTH), 25-hydroxy-vitamin D [25(OH)D], total alkaline phosphatase (ALP), bone alkaline phosphatase (BALP) and urinary C-terminal telopeptide of type 1 collagen (CTx) were measured at any time point. RESULTS: Mean LS BMD values significantly increased at 24 months compared to baseline (p < 0.0001); the corresponding Z-score values were -1.28 ± 1.23 at 24 months vs -2.46 ± 1.25 at baseline; corresponding mean Bone Mineral Apparent Density (BMAD) values were 0.335 ± 0.206 vs 0.464 ± 0.216. Mean serum levels of ALP, BALP and CTx significantly decreased from baseline to 24 months. By MXA, we observed a significant 19.1% reduction of the mean wedging index of vertebral reshaping at 12 months, and 38.4% at 24 months (p < 0.0001) and of the mean concavity index (16.3% at 12 months and 35.9% at 24 months; p < 0.0001). Vertebral reshaping was achieved for 66/88 (75%) wedge fractures and 59/70 (84%) concave fractures, but there were 4 incident mild fractures. Finally, VF rate was reduced at 24 months compared to baseline: 37/710 (5.2%) vs 158/710 (22.2%). CONCLUSION: Our study demonstrates the utility of VFA as a safe and alternative methodology in the follow-up of children and adolescents with OI.

Clinical value of negative 68Ga-PSMA PET/CT in the management of biochemical recurrent prostate cancer patients.

PURPOSE: To evaluate the clinical value of 68Ga-PSMA PET/CT negativity in patients with biochemical recurrent prostate cancer (BCR). METHODS: One hundred three BCR patients (median age, 70 years; median PSA, 0.47 ng/mL) with negative 68Ga-PSMA PET/CT, followed up for at least 1 year, were retrospectively identified in a database of 1003 consecutive patients undergoing 68Ga-PSMA PET/CT for BCR. Clinical recurrence (CR) was determined or excluded on follow-up imaging selected as per clinical practice. Clinical recurrence-free survival (CRFS) was computed from the date of negative 68Ga-PSMA PET/CT to the date of evident disease; frequencies of CRFS were described as per ISUP patient subset (subset 1: ISUP grades 1 and 2; subset 2: ISUP grade 3; subset 3: ISUP grades 4 and 5) and other conventional variables. RESULTS: In 57 patients out of 103 (55.3%), CR was detected in the prostatic fossa (45.6%), nodes (38.6%), and bone (15.8%). The median CRFS was 15.4 months (range, 12.1-20.5), with a CRFS at 12 months in 61.4% of cases (range, 50.9-70.4) whereas the 24-month CRFS was 34.8% (range, 24-45.8). ISUP subset 1 benefited from significantly longer CRFS compared to subset 2 and subset 3 (median CRFS, 20.5 months, 12.6 months, and 12.1 months, respectively). ISUP subset 3 had significantly poorer 24-month CRFS (9.3%) compared to subset 1 (47.8%) and subset 2 (33.5%). At the univariate and multivariate analyses, the ISUP subset was the only significant risk factor for clinical relapse; ISUP subset 3 and subset 2 patients held a higher risk of CR compared to subset 1 patients (HR of 2.75 [1.35-5.57] for subset 3 versus subset 1; HR of 2.08 [1.11-3.88] for subset 2 versus subset 1). CONCLUSION: 68Ga-PSMA PET/CT negativity in early BCR patients (PSA < 0.5 ng/mL) with low-grade primary prostate cancer (ISUP1 and 2) may support the exploration of a clinical surveillance approach in future prospective studies.

Ultrastructure study of skin fibroblasts in patients with Ehlers-Danlos Syndrome (EDS): preliminary results.

AIM OF THE STUDY: To investigate, in vivo and in vitro, the fibroblast-to-myofibroblast transition in patients with hypermobile Ehlers-Danlos Syndrome (EDS). To analyze the dermis of patients with classical form of EDS (cEDS) and with hEDS, to identify qualitative and/or quantitative differences in ECM component and ultrastructural changes in collagen. MATERIALS AND METHODS: Seven subjects, aged over 18, two with cEDS and five with hEDS underwent two skin biopsy. One sample was prepared for transmission electron microscopy (TEM), the other for immunofluorescence. The diameter of collagen fibers was measured with TEM. Fibrils were analyzed in four patients: the two with cEDS and two with hEDS. For each patient, the diameter of n=250 collagen fibrils was measured. αSMA was used as specific marker for myofibroblast to highlight their presence in vivo in the skin of patients with hEDS. RESULT: IF observation could not assess an increased expression of αSMA in hEDS patients, which showed no statistical difference compared to classic form patients. The major result from the analysis of TEM images is the clear difference in ECM composition between the two forms of EDS: ECM in hEDS is optically more dense and more prominently composed of elastic fibers. CONCLUSION: Our study provides the following important evidence: 1) the absence in vivo of dermal fibroblasts in patients with hEDS, demonstrated by αSMA negativity; 2) the presence of statistically significant changes in the diameter of collagen fibrils between the classic and the hypermobile forms.

The Horton-Rogers-Lapwood problem for an inclined porous layer with permeable boundaries.

A formulation of the Horton-Rogers-Lapwood problem for a porous layer inclined with respect to the horizontal and characterized by permeable (isobaric) boundary conditions is presented. This formulation allows one to recover the results reported in the literature for the limiting cases of horizontal and vertical layer. It is shown that a threshold inclination angle exists which yields an upper bound to a parametric domain where the critical wavenumber is zero. Within this domain, the critical Darcy-Rayleigh number can be determined analytically. The stability analysis is performed for linear perturbations. The solution is found numerically, for the inclination angles above the threshold, by employing a Runge-Kutta method coupled with the shooting method.

Correction to: 18F-NaF PET/CT: EANM procedure guidelines for bone imaging.

The original version of this article unfortunately contained an error. The name and affiliation of "Frédéric Paycha" needs to be corrected. Given in this article is the correct author name and affiliation.

Identification and characterization of a new potyvirus infecting cucurbits.

A new potyvirus, tentatively named cucurbit vein banding virus (CVBV), was identified in crops of cucurbits in San Pedro (Buenos Aires, Argentina). The complete genome sequences of two isolates of CVBV were obtained by next-generation sequencing (Illumina). The genomic RNA consisted of 9968 and 9813 nucleotides, respectively, and displayed typical potyvirus organization. The percentage identity for these two genome sequences, using BLASTn, was 77% to sweet potato virus c and 73% to tomato necrotic stunt virus. BLASTx analysis of the complete polyprotein showed that the most closely related virus is plum pox virus, with 48% amino acid sequence identity for both isolates. Sequence comparisons and phylogenetic analyses indicate that CVBV belongs to a previously undescribed species in genus Potyvirus.

Bisphosphonates therapy in children with Osteogenesis imperfecta: clinical experience in oral surgery.

OBJECTIVES: To define the possible complications of oral surgery in childhood in patients affected by type 1 Osteogenesis imperfecta (OI) and treated with bisphosphonates (BP). METHODS: The study was conducted among 20 patients in childhood with an age range 8-14 (12 ♂ e 8 ♀) affected by OI. Patients were initially evaluated at the Policlinico Umberto I, University Hospital of Rome, Rare Disease Center Skeletal Dysplasia-Bone Metabolic Pathologies and after at the Policlinico Umberto I, University Hospital of Rome, Head and Neck Department, UOC Pediatric Dentistry. RESULTS: From this experience, we showed that a proper patient management from the medical and dental point of view can protect these patients from the risk of post-operative problems, such as onj, soft tissue flogos, intraoral and extraoral fistulas, failure to heal the post-extractive alveolus, infections, post-operative pain and pathological fractures. The follow-up, ranging from a minimum of 2 years to a maximum of 5 years, have not demonstrated the presence of particular complications or healing defects. CONCLUSIONS: The clinical experiences observed in these patients are encouraging because no postoperative complications have been observed compared to patients non-affected by OI.

Clinical and biochemical response to neridronate treatment in a patient with osteoporosis-pseudoglioma syndrome (OPPG).

Osteoporosis-pseudoglioma syndrome (OPPG) is a rare autosomal recessive syndrome characterized by juvenile-onset osteoporosis and ocular abnormalities due to a low-density lipoprotein receptor-related protein 5 (LRP5) gene mutation. Treatment with bisphosphonates, particularly with pamidronate and risedronate, has been reported to be of some efficacy in this condition. We report on a patient with OPPG due to an LRP5 gene mutation, who showed an encouraging response after a 36-month period of neridronate therapy. We report a case of a patient treated with bisphosphonates. Bisphosphonates should be administered in OPPG patients as a first-line therapy during early childhood.

Serum creatine kinase isoenzymes in children with osteogenesis imperfecta.

This study evaluates serum creatine kinase isoenzyme activity in children with osteogenesis imperfecta to determine its usefulness as a biochemical marker during treatment with bisphosphonate. The changes of creatine kinase (CK) isoenzyme activity during and after discontinuation therapy were observed. These results could be useful in addressing over-treatment risk prevention. INTRODUCTION: The brain isoenzyme of creatine kinase (CKbb) is highly expressed in mature osteoclasts during osteoclastogenesis, thus plays an important role in bone resorption. We previously identified high serum CKbb levels in 18 children with osteogenesis imperfect (OI) type 1 treated for 1 year with bisphosphonate (neridronate). In the present study, serum CK isoenzymes were evaluated in the same children with continuous versus discontinued neridronate treatment over a further 2-year follow-up period. METHODS: This study included 18 children with OI type 1, 12 with continued (group A) and 6 with ceased (group B) neridronate treatment. Auxological data, serum biochemical markers of bone metabolism, bone mineral density z-score, and serum total CK and isoenzyme activities were determined in both groups. RESULTS: Serum CKbb was progressively and significantly increased in group A (p < 0.004) but rapidly decreased to undetectable levels in group B. In both groups, the cardiac muscle creatine kinase isoenzyme (CKmb) showed a marked decrease, while serum C-terminal telopeptide (CTx) levels were almost unchanged. CONCLUSIONS: This study provides evidence of the cumulative effect of neridronate administration in increasing serum CKbb levels and the reversible effect after its discontinuation. This approach could be employed for verifying the usefulness of serum CKbb as a biochemical marker in patients receiving prolonged bisphosphonate treatment. Moreover, the decreased serum CKmb levels suggest a systemic effect of these drugs.

(18)F-NaF PET/CT: EANM procedure guidelines for bone imaging.

The aim of this guideline is to provide minimum standards for the performance and interpretation of (18)F-NaF PET/CT scans. Standard acquisition and interpretation of nuclear imaging modalities will help to provide consistent data acquisition and numeric values between different platforms and institutes and to promote the use of PET/CT modality as an established diagnostic modality in routine clinical practice. This will also improve the value of scientific work and its contribution to evidence-based medicine.

Reliability of vertebral fractures assessment (VFA) in children with osteogenesis imperfecta.

The aim of this study is to evaluate the diagnostic accuracy of vertebral fractures assessment (VFA) in comparison with conventional radiography in identifying vertebral fractures in children and adolescents affected by OI. On 58 patients (33 males, 25 females; age range 1-18 years; 41 children and 17 adolescents) with osteogenesis imperfecta (OI type I, n = 44, OI type III, n = 4; OI type IV, n = 10), lateral spine images by radiographs and by dual-energy X-ray absorptiometry (DXA) were acquired. For vertebral fracture diagnosis, plain radiographs were used as "gold standard" and VFA and morphometric X-ray absorptiometry (MXA) were performed. The visualized vertebrae were 738 (97.9%) by radiographs and 685 (90.9%) by DXA of a total of 754 vertebrae from T4 to L4. VFA and MXA identified, respectively, 129 (74%) and 116 (66%) of the 175 vertebral fractures detected by radiographs. Radiographs identified 36 patients with vertebral fractures, VFA 35 and MXA 41 (6 false positives). On a per vertebra basis, radiographs and VFA had elevated agreement (93.9%; k score 0.81, 95% CI 0.76-0.86), that resulted slightly lower for MXA (90.6%; k score 0.72, 95% CI 0.65-0.78). VFA and MXA demonstrated high sensitivity (95.6 and 94.1 %, respectively) while specificity was 100% for VFA and 90.6% for MXA on a per patient basis; the agreement was excellent for VFA (98.3%; k score 0.96, 95% CI 0.89-1.03) and good for MXA (87.9%; k score 0.73, 95% CI 0.55-0.91). The diagnostic performance parameters resulted better for VFA (sensitivity 95.6%; specificity 100%; PPV 100%; NPV 97.2%), than for MXA (sensitivity 94.1%; specificity 85.4%; PPV 72.7%; NPV 97.2%). The results of our study demonstrate the reliability of VFA for diagnosis of vertebral fractures in children with OI suggesting its use as a more safe and practical alternative to conventional radiography.

Striking differences in the biological and molecular properties of onion and garlic isolates of onion yellow dwarf virus.

Complete nucleotide (nt) and deduced amino acid sequences of two onion yellow dwarf virus (OYDV) isolates showing mild and severe symptoms in onion but being unable to infect garlic were determined. The genomes consisted of 10,459 and 10,461 nt (without the 3' poly(A) tail) and were 92.2 % identical. Comparison of their whole genomes, polyproteins and P1, HC-Pro, P3, CI, VPg and NIa-Pro regions with those of garlic isolates previously identified as OYDV gave percentage values below that proposed as the molecular threshold for potyvirus species demarcation. This and the striking differences in host range between onion and garlic isolates suggest that they represent different virus species.

Taurine deficiency in thalassemia major-induced osteoporosis treated with neridronate.

The aetiology of thalassemia major-induced osteoporosis is multifactorial. Up to now, bisphosphonates seem to be a promising therapy. Taurine is found in a high concentration in bone cells enhancing bone tissue formation and inhibiting bone loss. Recently we found a decrease taurine plasma level in children affected by osteogenesis imperfecta during neridronate (amino-bisphosphonate) therapy suggesting a possible interaction between pharmacological effect of this drug and taurine availability. On the basis of these results, we performed plasma and urine amino acid (AA) analysis in thalassemia major-induced osteoporosis before and after 12 months of neridronate treatment. Twelve patients, five males and seven females, aged from 20 to 29 years following a hypertransfusion treatment protocol were enrolled in the study. Patients were treated with neridronate infusion every one month (30 mg in 100ml of saline). Plasma and urine specimens for AA analysis, bone mineral density, bone mineral content and vertebral project area were examined at baseline (T0) and after 12 months of treatment (T12). A significant decrease was observed for plasma level and urinary excretion of taurine (T0 vs. T12=p<0.01) whereas bone mineral content and vertebral projection area showed a statistical significant increase (T0 vs. T12=p<0.05). These results and other experimental researches warrant further studies examining the long-term effect of taurine supplementation in association with neridronate treatment.

An apparatus for simultaneous thermodynamic and optical measurements, with large temperature excursions.

We report the design and realization of an integrated system for measuring, at the same time, the thermodynamic and spectroscopic features of nanoporous materials interesting for hydrogen storage purposes. The whole investigation cycle, from thermal activation to the actual investigation of uptake and release of hydrogen, is carried out in the same vacuum tight vessel, equipped with an optical window, whose temperature can range between 10 and 750 K, up to a maximum pressure of 50 bars. The system has been designed to investigate properties of carbon nanotubes but its use can be extended to any kind of nanoporous sample such as, for example, carbon nanofibers, zeolytes, metal organic frameworks, and similar materials.

Absence of severe recurrent infections in glycogen storage disease type Ib with neutropenia and neutrophil dysfunction.

We describe a 10-year-old boy with glycogen storage disease type Ib (GSD Ib) with neutropenia and neutrophil dysfunction who never suffered from severe recurrent infections. Lymphocyte subpopulations and assay of intracellular cytokines (IL-2, IL-4 and IFN-gamma) showed a pattern of lymphocyte activation suggesting a shift of T(H)1/T(H)2 balance towards a T(H)1 response. This is the first report of GSD Ib without severe recurrent infections in spite of neutropenia and neutrophil dysfunction.

Density of phonon states in solid parahydrogen from inelastic neutron scattering.

We have measured the inelastic neutron scattering spectrum of solid parahydrogen (at low pressure and T=13.3 K) using the thermal original spectrometer with cylindrical analyzers spectrometer at the ISIS pulsed neutron source (UK). From the experimental spectrum we have obtained the parahydrogen density of phonon states which has been compared with the estimates available in the literature. The present determination improves substantially the previous experimental scenario from the point of view of both statistics and accuracy. The comparison with the most recent estimate obtained from a quantum mechanical simulation of the molecular dynamics calls for an improvement of the computational methods..

Microscopic self-dynamics in liquid hydrogen and in its mixtures with deuterium.

We have measured the dynamic structure factor of liquid parahydrogen, pure and mixed with deuterium, in various thermodynamic conditions using incoherent inelastic neutron scattering. The experiments were carried out on TOSCA-II, a new time-of-flight, inverse-geometry, crystal-analyzer spectrometer. After an accurate data reduction, the high-energy parts of the neutron spectra recorded in backward scattering were studied through the modified Young and Koppel model, from which the mean kinetic energy values for a hydrogen molecule were estimated. In addition the low-energy parts of the neutron spectra recorded in forward scattering were analyzed in the framework of the Gaussian approximation and fitted through a Levesque-Verlet model for the velocity autocorrelation function. Thus various physical quantities are determined and compared with accurate path integral Monte Carlo simulations. Despite the excellent quality of these fits, the velocity autocorrelation functions derived from the forward-scattering data appear totally unable to properly describe the backward-scattering ones. These findings prove an unquestionable breakdown of the Gaussian approximation in semiquantum liquids. The present results appear of great interest and suggest further investigation on the limits of the widely used Gaussian approximation.