Microstructural defects in nanocrystalline iron probed by x-ray-absorption spectroscopy

An EXAFS (extended x-ray-absorption fine structure) study of nanocrystalline iron prepared by high-energy ball milling is presented. Accurate data analysis has been performed using a recently developed ab initio multiple-scattering method (GNXAS). The crystalline iron EXAFS spectrum, taken as reference, has been analyzed taking proper account of the important multiple-scattering signal. Results of the data analysis are shown to be in good agreement with known structural values. The dramatic decrease of the first-neighbor coordination number found in nanocrystalline iron, as a function of the milling time, is shown to be related to the presence of a large defect density. The corresponding decrease of the coordination numbers of the second and further neighbors, as well as the significant decrease of the multiplicities of the three-atom configurations, confirms this interpretation. A simple model which takes into account the presence of atomic defects is shown to lead to marked reduction of coordination numbers and three-atom multiplicities in agreement with the experimental data. Selected models without lattice defects are shown to be unable to give a quantitative explanation of the intensity reduction of the EXAFS signal found in milled nanocrystalline iron. An in situ annealing of the sample (up to about 1100 °C) milled for the longer time (32 h) is shown to reduce considerably the density of the defects, as expected, although no complete recovering of the crystalline order is found. The transition from α iron to γ iron has been directly observed for such nanocrystalline material

t cell mediated rejection of human cd34 cells is prevented by costimulatory blockade in a xenograft model

Abstract A xenograft model of stem cell rejection was developed by co-transplantating human CD34 + and allogeneic CD3 + T cells into NOD-scid ɣ-chain null mice. T cells caused graft failure when transplanted at any CD34/CD3 ratio between 1:50 and 1:.1. Kinetics experiments showed that 2 weeks after transplantation CD34 + cells engrafted the marrow and T cells expanded in the spleen. Then, at 4 weeks only memory T cells populated both sites and rejected CD34 + cells. Blockade of T cell costimulation was tested by injecting the mice with abatacept (CTLA4-IgG1) from day –1 to +27 (group A), from day –1 to +13 (group B), or from day +14 to +28 (group C). On day +56 groups B and C had rejected the graft, whereas in group A graft failure was completely prevented, although with lower stem cell engraftment than in controls ( P  = .03). Retransplantation of group A mice with same CD34 + cells obtained a complete reconstitution of human myeloid and B cell lineages and excluded latent alloreactivity. In this first xenograft model of stem cell rejection we showed that transplantation of HLA mismatched CD34 + cells may be facilitated by treatment with abatacept and late stem cell boost

Opinion, knowledge, and clinical experience with functional neurological disorders among Italian neurologists: results from an online survey

Background: Functional neurological disorders (FND) are disabling medical conditions commonly seen in neurological practice. Neurologists play an essential role in managing FND, from establishing a diagnosis to coordination of multidisciplinary team-based treatment for patients. With this study, we investigated the knowledge and the clinical experience of Italian neurologists in managing patients with FND. Methods: Members of the Italian Society of Neurology were invited via e-mail to participate in this ad hoc online survey; 492 questionnaires were returned completed. Results: The term "Functional neurological disorders" in reference to FND was used more frequently than other psychological (e.g., psychogenic or conversion), or descriptive terms (e.g., non-organic or stress-related). When speaking with patients, the respondents stated that they preferred explaining symptoms based on abnormal functioning of the nervous system than discussing mental illness and that they would refer their patient to a psychologist rather than to a psychiatrist. Few considered that physiotherapy and psychiatric interventions are useful approaches to treating FND. Some believed that patients simulate their symptoms. Conclusions: Overall, the responses suggest that knowledge about scientific advances in FND is somewhat sparse. A psychiatric-centered view of FND opens the way to an approach in which neurobiological and psychological aspects constitute essential factors of the condition. In this context, professional education could improve understanding of FND and optimize patient management

Towards a Long-Read Sequencing Approach for the Molecular Diagnosis of RPGRORF15 Genetic Variants

Sequencing of the low-complexity ORF15 exon of RPGR, a gene correlated with retinitis pigmentosa and cone dystrophy, is difficult to achieve with NGS and Sanger sequencing. False results could lead to the inaccurate annotation of genetic variants in dbSNP and ClinVar databases, tools on which HGMD and Ensembl rely, finally resulting in incorrect genetic variants interpretation. This paper aims to propose PacBio sequencing as a feasible method to correctly detect genetic variants in low-complexity regions, such as the ORF15 exon of RPGR, and interpret their pathogenicity by structural studies. Biological samples from 75 patients affected by retinitis pigmentosa or cone dystrophy were analyzed with NGS and repeated with PacBio. The results showed that NGS has a low coverage of the ORF15 region, while PacBio was able to sequence the region of interest and detect eight genetic variants, of which four are likely pathogenic. Furthermore, molecular modeling and dynamics of the RPGR Glu-Gly repeats binding to TTLL5 allowed for the structural evaluation of the variants, providing a way to predict their pathogenicity. Therefore, we propose PacBio sequencing as a standard procedure in diagnostic research for sequencing low-complexity regions such as RPGRORF15, aiding in the correct annotation of genetic variants in online databases

ChatGPT in orthopedics: a narrative review exploring the potential of artificial intelligence in orthopedic practice

The field of orthopedics faces complex challenges requiring quick and intricate decisions, with patient education and compliance playing crucial roles in treatment outcomes. Technological advancements in artificial intelligence (AI) can potentially enhance orthopedic care. ChatGPT, a natural language processing technology developed by OpenAI, has shown promise in various sectors, including healthcare. ChatGPT can facilitate patient information exchange in orthopedics, provide clinical decision support, and improve patient communication and education. It can assist in differential diagnosis, suggest appropriate imaging modalities, and optimize treatment plans based on evidence-based guidelines. However, ChatGPT has limitations, such as insufficient expertise in specialized domains and a lack of contextual understanding. The application of ChatGPT in orthopedics is still evolving, with studies exploring its potential in clinical decision-making, patient education, workflow optimization, and scientific literature. The results indicate both the benefits and limitations of ChatGPT, emphasizing the need for caution, ethical considerations, and human oversight. Addressing training data quality, biases, data privacy, and accountability challenges is crucial for responsible implementation. While ChatGPT has the potential to transform orthopedic healthcare, further research and development are necessary to ensure its reliability, accuracy, and ethical use in patient care

Candidurie nosocomiali: analisi dei fattori di rischio, terapia ed evoluzione micologica. Risultati di una indagine nazionale

The multiple problems associated with the recovery of yeasts from urine specimens induced the Medical Mycology Committee (CoSM) of AMCLI to run a nationwide epidemiologic survey on candiduria in order to evaluate risk factors, involved species, treatment and outcome. Ten hospitals (Bergamo, Como, Crema, Novara,Varese,Ancona, Florence, Pescara, Palermo and Taranto) participated to this study, which was run on a 15-month period (October 1, 2001-December 31, 2002). Overall, 83 Data Forms were collected, regarding patients admitted to Intensive Care Units (45), Surgical (9) and Medical (29) wards. The most common risk factors were: bladder catheter, antibiotic therapy, parenteral nutrition, kidney failure, surgery. Candiduria, mostly asymptomatic, were often associated with fever and bacterial infections. Concurrent candidaemia was detected in 13 patients. Candida albicans was the most frequently recovered species, from both urine and blood, followed by C. glabrata. Other Candida species were occasionally isolated from urine specimens. Specific antifungal treatment was administered to 58% of the patients, mostly using fluconazole. The remaining subjects did not receive antimycotic therapy. Eradication of Candida from urine specimens was observed even without a specific therapy