198 research outputs found
Macroscopic quantum tunnelling of Bose-Einstein condensates in a finite potential well
Bose-Einstein condensates are studied in a potential of finite depth which
supports both bound and quasi-bound states. This potential, which is harmonic
for small radii and decays as a Gaussian for large radii, models experimentally
relevant optical traps. The nonlinearity, which is proportional to both the
number of atoms and the interaction strength, can transform bound states into
quasi-bound ones. The latter have a finite lifetime due to tunnelling through
the barriers at the borders of the well. We predict the lifetime and stability
properties for repulsive and attractive condensates in one, two, and three
dimensions, for both the ground state and excited soliton and vortex states. We
show, via a combination of the variational and WKB approximations, that
macroscopic quantum tunnelling in such systems can be observed on time scales
of 10 milliseconds to 10 seconds.Comment: J. Phys. B: At. Mol. Opt. Phys. in pres
Enhanced biomedical heat-triggered carriers via nanomagnetism tuning in ferrite-based nanoparticles
Biomedical nanomagnetic carriers are getting a higher impact in therapy and
diagnosis schemes while their constraints and prerequisites are more and more
successfully confronted. Such particles should possess a well-defined size
with minimum agglomeration and they should be synthesized in a facile and
reproducible high-yield way together with a controllable response to an
applied static or dynamic field tailored for the specific application. Here,
we attempt to enhance the heating efficiency in magnetic particle hyperthermia
treatment through the proper adjustment of the core–shell morphology in
ferrite particles, by controlling exchange and dipolar magnetic interactions
at the nanoscale. Thus, core–shell nanoparticles with mutual coupling of
magnetically hard (CoFe2O4) and soft (MnFe2O4) components are synthesized with
facile synthetic controls resulting in uniform size and shell thickness as
evidenced by high resolution transmission electron microscopy imaging,
excellent crystallinity and size monodispersity. Such a magnetic coupling
enables the fine tuning of magnetic anisotropy and magnetic interactions
without sparing the good structural, chemical and colloidal stability.
Consequently, the magnetic heating efficiency of CoFe2O4 and MnFe2O4
core–shell nanoparticles is distinctively different from that of their
counterparts, even though all these nanocrystals were synthesized under
similar conditions. For better understanding of the AC magnetic hyperthermia
response and its correlation with magnetic-origin features we study the effect
of the volume ratio of magnetic hard and soft phases in the bimagnetic
core−shell nanocrystals. Eventually, such particles may be considered as novel
heating carriers that under further biomedical functionalization may become
adaptable multifunctional heat-triggered nanoplatforms
Perception and Understanding of Greek Dentists on Periodontal Regenerative Procedures: A Questionnaire Based Study
Objectives: The aim of this cross-sectional questionnaire study was to evaluate the perception and preferences of Greek dentists who either specialised
in or had an interest in periodontal regenerative procedures and to compare the results with corresponding findings from two previous studies from
different countries.
Materials and methods: The questionnaire was divided in two main sections and included multiple choice and/or open/closed questions. The first
section consisted of six questions and was designed to collect demographic data of the sample and the second section, consisting of 15 questions,
included general questions regarding periodontal regeneration procedures and questions based on specific clinical cases. 200 questionnaires were
distributed at selected venues in Greece by the investigators. The participants were given one month to complete and return to the questionnaires to the
School of Dentistry in Thessaloniki.
Statistical analysis: Data management and analysis was performed using both Microsoft Excel 2007® (Microsoft Corporation, Reading, UK) and SPSS®
version 22.0 software (IBM United Kingdom Ltd, Portsmouth, UK). Frequencies and associations between the demographic profiles of the participants
were evaluated and presented in the form of frequency tables, charts, and figures.
Results: 104 questionnaires (67 males, 37 females: mean age 43.2 years [±9.8]) (52% response rate) were received. Of those who responded 56.7% (n=59)
specialized in Periodontics and 43.3% (n=45) specialized in a variety of other dental disciplines (General Dentistry, Oral Surgery and Implantology).
Guided tissue regeneration procedures and the use of enamel matrix derivative were recommended for the reconstruction of bony defects and both
subepithelial connective tissue graft and coronally advanced flap with or without enamel matrix derivative were the most popular choices for root
coverage. Smoking was considered a contraindication by most of the participants and conflicting responses were given regarding the use of antibiotics
as part of the post-operative care following regenerative procedures.
Conclusions: The participants incorporated both traditional and “novel” techniques and products in reconstructive procedures and appeared to be up
to date with the evidence from the dental literature. However, it was evident that there was confusion regarding the role of antibiotics in regenerative
procedures
Relationships Among Gingival Crevicular Fluid Biomarkers, Clinical Parameters of Periodontal Disease, and the Subgingival Microbiota
Background The objectives were to measure the levels of gingival crevicular fluid (GCF) biomarkers and subgingival bacterial species in periodontally healthy and periodontitis subjects in order to explore relations among these biomarkers, the subgingival microbiota, and clinical parameters of periodontal disease. Material and methods Clinical periodontal parameters were measured at 6 sites per tooth in 20 periodontitis and 20 periodontally healthy subjects. GCF and subgingival plaque samples were obtained from the mesiobuccal aspect of every tooth. GCF levels of interleukin-1β (IL-1β), matrix metalloproteinase-8 (MMP-8) and IL-8 were measured using checkerboard immunoblotting and the levels of 40 bacterial taxa quantified using checkerboard DNA-DNA hybridization. A subset of “clinically healthy” (CH) sites from each group was analyzed separately. Significance of differences between groups was determined using the unpaired t-test or the Mann-Whitney test. Correlations among immunological, microbiological and clinical data were determined using the Spearman rank correlation coefficient. Results There were positive correlations among mean clinical parameters and mean levels of the 3 biomarkers and proportions of Orange and Red complex species (p\u3c0.05). CH sites from periodontitis subjects had higher levels of IL-1β and IL-8 and higher proportions of Orange and Red complex species (p\u3c0.05) than CH sites from periodontally healthy subjects. Red complex species were positively associated with the expression of all biomarkers (p\u3c0.05), while Purple and Yellow complex species had negative correlations with IL-1β and IL-8 (p\u3c0.05). Conclusions CH sites from periodontitis subjects present higher levels of GCF biomarkers and periodontal pathogens than CH sites from periodontally healthy subjects. Different microbial complexes demonstrated distinct associations with specific GCF biomarkers
A Survey of Dentists in the Management of Dentine Hypersensitivity: A Questionnaire-based Study.
OBJECTIVE: Previous studies have indicated that dentists may be uncertain about the etiology, diagnosis, and effective management of dentine sensitivity/dentine hypersensitivity (DH).: The purpose of the present study was to evaluate the knowledge and understanding of Greece-based dental professionals in treating DH.: MATERIALS AND METHODS: A 26-item questionnaire was sent to a representative sample of Greek dentists. RESULTS: Two hundred thirty questionnaires were originally provided to the participants and of the 210 questionnaires that were returned, 191 questionnaires (90 M; 86 F; mean age 36.26 years [standard deviation: 11.34]) were included for analysis, a response rate of 83% was observed. 39.8% of dentists indicated that 1 in 10 of their patients experienced discomfort from DH with 76.4% of dentists indicating that their patients initiated the conversation on DH. In contrast, 44% of the dentists indicated that they initiated the relevant conversation. 34.9% of dentists indicated that the duration of discomfort lasted up to 3 weeks and 76.4% indicated that DH had an impact on their patients' quality of life. Incorrect tooth brushing was considered to be a major etiological factor (68.6%) with "air blast" (37.3%) and "probing" (15%) as the main methods for identification. 83.6% of dentists indicated that they were confident in recommending over-the-counter products for home use. CONCLUSION: The results of this study suggest that in terms of knowledge and understanding of DH, there is still confusion concerning some aspects of the diagnosis and management of the condition
Multifunctional nanocomposites of poly(vinylidene fluoride) reinforced by carbon nanotubes and magnetite nanoparticles
In the present study, the effect of nano magnetite (Fe3O4) content on structural, dielectric/electrical, magnetic and thermal properties of poly(vinylidene fluoride)/carbon nanotubes matrix, is investigated. Nanocomposite films of polyvinylidene fluoride, carbon nanotubes and Fe3O4 nanoparticles were prepared by the twin screw compounding method. Fe3O4, as magnetic inclusions was incorporated into the composites with carbon nanotubes loadings well above the percolation threshold, where conductive networks were formed. Magnetic characterization revealed the ferrimagnetic behavior of nanocomposites, with saturation magnetization values depending on magnetite content. Results obtained from the analysis of Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) techniques were very informative for the study of the polymorphism and crystallinity in PVDF. The incorporation of Fe3O4 inclusions in PVDF/CNT matrix, gradually increase both electrical conductivity and dielectric permittivity up to 10 wt% Fe3O4 content, while at the higher Fe3O4 content (15 wt%) reduced values were obtained. This behavior, at higher Fe3O4 content, should be possible related to the insulating and barrier role of Fe3O4 nanoparticles
Analysis of data collected in the European Society for Blood and Marrow Transplantation (EBMT) Registry on a cohort of lymphoma patients receiving plerixafor
Plerixafor + granulocyte-colony stimulating factor (G-CSF) is administered to patients with lymphoma who are poor mobilizers of hematopoietic stem cells (HSCs) in Europe. This international, multicenter, non-interventional registry study (NCT01362972) evaluated long-term follow-up of patients with lymphoma who received plerixafor for HSC mobilization versus other mobilization methods. Propensity score matching was conducted to balance baseline characteristics between comparison groups. The following mobilization regimens were compared: G-CSF + plerixafor (G + P) versus G-CSF alone; G + P versus G-CSF + chemotherapy (G + C); and G-CSF + plerixafor + chemotherapy (G + P + C) versus G + C. The primary outcomes were progression-free survival (PFS), overall survival (OS), and cumulative incidence of relapse (CIR). Overall, 313/3749 (8.3%) eligible patients were mobilized with plerixafor-containing regimens. After propensity score matching, 70 versus 36 patients were matched in the G + P versus G-CSF alone cohort, 124 versus 124 in the G + P versus G + C cohort, and 130 versus 130 in the G + P + C versus G + C cohort. For both PFS and OS, the upper bound of confidence interval for the hazard ratio was >1.3 for all comparisons, implying that non-inferiority was not demonstrated. No major differences in PFS, OS, and CIR were observed between the plerixafor and comparison groups
Genetic justification of COVID-19 patient outcomes using DERGA, a novel data ensemble refinement greedy algorithm
Complement inhibition has shown promise in various disorders, including COVID-19. A prediction tool including complement genetic variants is vital. This study aims to identify crucial complement-related variants and determine an optimal pattern for accurate disease outcome prediction. Genetic data from 204 COVID-19 patients hospitalized between April 2020 and April 2021 at three referral centres were analysed using an artificial intelligence-based algorithm to predict disease outcome (ICU vs. non-ICU admission). A recently introduced alpha-index identified the 30 most predictive genetic variants. DERGA algorithm, which employs multiple classification algorithms, determined the optimal pattern of these key variants, resulting in 97% accuracy for predicting disease outcome. Individual variations ranged from 40 to 161 variants per patient, with 977 total variants detected. This study demonstrates the utility of alpha-index in ranking a substantial number of genetic variants. This approach enables the implementation of well-established classification algorithms that effectively determine the relevance of genetic variants in predicting outcomes with high accuracy
Genetic prediction of ICU hospitalization and mortality in COVID-19 patients using artificial neural networks
There is an unmet need of models for early prediction of morbidity and mortality of Coronavirus disease-19 (COVID-19). We aimed to a) identify complement-related genetic variants associated with the clinical outcomes of ICU hospitalization and death, b) develop an artificial neural network (ANN) predicting these outcomes and c) validate whether complement-related variants are associated with an impaired complement phenotype. We prospectively recruited consecutive adult patients of Caucasian origin, hospitalized due to COVID-19. Through targeted next-generation sequencing, we identified variants in complement factor H/CFH, CFB, CFH-related, CFD, CD55, C3, C5, CFI, CD46, thrombomodulin/THBD, and A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS13). Among 381 variants in 133 patients, we identified 5 critical variants associated with severe COVID-19: rs2547438 (C3), rs2250656 (C3), rs1042580 (THBD), rs800292 (CFH) and rs414628 (CFHR1). Using age, gender and presence or absence of each variant, we developed an ANN predicting morbidity and mortality in 89.47% of the examined population. Furthermore, THBD and C3a levels were significantly increased in severe COVID-19 patients and those harbouring relevant variants. Thus, we reveal for the first time an ANN accurately predicting ICU hospitalization and death in COVID-19 patients, based on genetic variants in complement genes, age and gender. Importantly, we confirm that genetic dysregulation is associated with impaired complement phenotype
Genetic justification of COVID-19 patient outcomes using DERGA, a novel data ensemble refinement greedy algorithm.
Complement inhibition has shown promise in various disorders, including COVID-19. A prediction tool including complement genetic variants is vital. This study aims to identify crucial complement-related variants and determine an optimal pattern for accurate disease outcome prediction. Genetic data from 204 COVID-19 patients hospitalized between April 2020 and April 2021 at three referral centres were analysed using an artificial intelligence-based algorithm to predict disease outcome (ICU vs. non-ICU admission). A recently introduced alpha-index identified the 30 most predictive genetic variants. DERGA algorithm, which employs multiple classification algorithms, determined the optimal pattern of these key variants, resulting in 97% accuracy for predicting disease outcome. Individual variations ranged from 40 to 161 variants per patient, with 977 total variants detected. This study demonstrates the utility of alpha-index in ranking a substantial number of genetic variants. This approach enables the implementation of well-established classification algorithms that effectively determine the relevance of genetic variants in predicting outcomes with high accuracy
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