247 research outputs found
On the Pairing Structure of the Vacuum induced by a Magnetic Field in 2+1-dimensional Dirac Field Theory
Using a sequence of Bogoliubov transformations, we obtain an exact expression
for the vacuum state of a Dirac field in 2+1 dimensions in presence of a
constant magnetic field. This expression reveals a peculiar two level pairing
structure for any value of the mass m greater than zero. This calculation
clarifies the nature of the condensate in the lowest Landau level whose
existence has been emphasized recently by a several authors.Comment: 10 pages, AMSLaTeX (with LaTe2e), no figures (to be published in
Phys. Lett. B
Current Trends in Skeletal Borderline Patients: Surgical versus Orthodontic Treatment Decisions—What Is the Evidence?
Background: The aim is to assess the current evidence-based knowledge about treatment decisions for skeletal malocclusion in adult borderline patients. Methods: A literature search was con-ducted through three databases. Inclusion criteria were restricted to systematic reviews, prospective, retrospective, and control studies. Only articles comparing orthodontic camouflage and orthog-nathic surgical treatment for Class II and Class III malocclusions in adult patients were selected to be reviewed. Results: Seven articles concerning Class II and nine concerning Class III met the inclusion criteria. Scientific evidence was poor due to low methodological quality. Conclusions: Surgical treatment was found to better improve skeletal and soft-tissue cephalometric values, whereas camouflage treatment mainly involved dentoalveolar movements. Aesthetic changes, as perceived by the patient, were not significantly different in the two groups. Recently improved surgical techniques, differing from those described in the analyzed articles, may provide similar or more stable outcomes compared with orthodontic-only treatment. Although some cephalometric variables can be helpful, the most important parameters for treatment selection are the patient’s presenting complaint and their self-image perception. Further studies with larger sample sizes and similar pretreatment conditions, and considering patient self-evaluation of esthetics and function, should be undertaken
Epicardial fat, gender, and cardiovascular risk
Epicardial fat (EF) is considered an important risk factor and an active player in the pathogenesis of cardiovascular and metabolic diseases. EF is an endocrine organ that releases hormones and mediators, including the circulating C-reactive protein (CRP), and plays a vital role in modifying the vascular endothelial function and promoting the growth of coronary atherosclerosis. This study aimed to investigate the relationship between CRP concentrations and EF in a cohort of patients with metabolic syndrome at risk for coronary artery disease. In our study, carried out in primary prevention, we enrolled 36 subjects (M/F: 21/15; age: 59.3±0.79 yrs) diagnosed with metabolic syndrome. We have classified the patients into two groups: Men and Women. Besides anthropometric characterization and screening laboratory tests, the subjects performed a multidetector computed tomography scan, which allowed the EF quantification. Mean EF was 115.1 cc in the study population. The average EF of women was 111 cc; the average EF of men was 118 cc (P=0.18). CRP levels were strongly positively correlated with EF area in women (P=0.01), while the correlation was not found in men (P=0.4). Our findings suggest that, in women, the EF produces a greater amount of acute-phase proteins and increases the pro-inflammatory state in the epicardial region. For this reason, we can hypothesize, in women, a different role in the development of atherosclerotic plaque of the epicardial fat compared to men
Syncope and Cannabis: hypervagotonia from chronic abuse? A case report and literature review
Background: Cannabis is the most consumed drug worldwide and number of users is increasing, particularly among youth. Moreover, cannabis potential therapeutic properties have renewed interest to make it available as a treatment for a variety of conditions. Albeit rarely, cannabis consumption has been associated with cardiovascular diseases such as arrhythmias, myocardial infarction (MI) and potentially sudden death. Case presentation: A 24-year-old woman presented to the emergency department sent by her cardiologist because of a recent finding of a 16 seconds asystole on the implantable loop recorder (ILR) she implanted 7 months before for recurrent syncopes. She declared that she is a heavy cannabis user (at least 5 cannabis-cigarette per day, not mixed up with tobacco, for no less than 12 years) and all syncopes occurred shortly after cannabis consumption. After a collective discussion with the heart team, syncope unit, electrophysiologists and toxicologist, we decided to implant a dual chamber pacemaker with a rate response algorithm due to the high risk of trauma of the syncopal episodes. 24 months follow-up period was uneventful. Conclusions: Cannabis cardiovascular effects are not well known and, although rare, among these we find ischemic episodes, tachyarrhythmias, symptomatic sinus bradycardia, sinus arrest, ventricular asystole and possibly death. Because of cannabis growing consumption both for medical and recreational purpose, cardiovascular diseases associated with cannabis use may become more and more frequent. In the light of the poor literature, we believe that cannabis may produce opposite adverse effects depending on the duration of the habit. Acute administration increases sympathetic tone and reduces parasympathetic tone; conversely, with chronic intake an opposite effect is observed: repetitive dosing decreases sympathetic activity and increases parasympathetic activity. Clinicians should be aware of the increased risk of cardiovascular complications associated with cannabis use and should investigate its consumption especially in young patients presenting with cardiac dysrhythmias
Interactions between the Multicolored Asian Lady Beetle Harmonia axyridis and the Parasitoid Dinocampus coccinellae
Harmonia axyridis (Pallas) has been introduced either intentionally or accidentally in
different areas outside its native range, where it is often regarded as invasive. Dinocampus coccinellae (Schrank) has been recorded to parasitize H. axyridis in the field, both in the native and introduced areas, Italy included. The percent of parasitism found in our field investigation was low (four percent).The effect of exposure time of H. axyridis to D. coccinellae and the impact of parasitization on host longevity, oviposition capacity and egg fertility were evaluated in the laboratory. The acceptance and
suitability of H. axyridis as host for D. coccinellae were then studied, in comparison with the native coccinellid Adalia bipunctata (L.), which shares the same ecological niche. The effects of parasitization on female longevity and reproduction capacity in the exotic vs. the indigenous lady beetle were also investigated. The overall results showed that D. coccinellae negatively affected the fitness of H. axyridis, more than that of A. bipunctata. The parasitoid may thus play a marginal role in controlling the populations of the Asian lady beetle, without representing a threat to A. bipunctata
Use of the international classification of diseases (ICD)-11 method applied to veterinary forensic pathology for coding the cause and manner of death in wildlife
The growth of human population has led, in recent years, to increasingly frequent contacts with the wild animals with which we share the territory, sometimes leading to negative interactions with them. The purpose of the study is to apply the codes contained in the 11th Revision of the International Classification of Diseases (ICD-11) method to investigate the cause and the manner of death, also to entrust the veterinarian with the task of recognizing and describing a suspected animal abuse as a sentinel indicator of violence toward humans and non-humans, thus expanding the concept of “One Health” from a forensic investigation perspective. The subjects recruited are wild mammals submitted for autopsy to the Pathology Unit of the Department of Veterinary Science, University of Parma, Italy, from 2015 to 2018. The manner and the cause of death of 167 wild animals of 16 different species have been investigated. When possible, an on-site inspection where the corpse was found was performed. Injuries were classified according to the on-line 11th Revision of the International Classification of Diseases method. Section 22 (Injury, poisoning or certain other consequences of external causes) was used to record the “immediate cause of death” (cause of death) and Section 23 (External causes of morbidity or mortality) was used to record the “underlying cause of death” (manner of death) for each animal. In most cases, death occurred as a result of road trauma but in some cases, abuse and voluntary killing were investigated. The recognition of non-accidental injuries is particularly important for both the defense in court of animals and for the connection between crimes committed against animals and against humans, known as “The Link”. The use of the ICD-11 method, as a sort of summary of the autopsy report, was confirmed to be of great value for the clarity and simplicity of processing the data collected also by veterinary pathologists. The veterinary pathologists can use this evidence-based method with the aim of creating a national register and therefore, to understand the real extent of the human impact on wildlife and document it in a scientific and statistically usable way
Novel positive allosteric modulators of A2B adenosine receptor acting as bone mineralisation promoters
Small-molecules acting as positive allosteric modulators (PAMs) of the A2B adenosine receptor (A2B AR) could potentially represent a novel therapeutic strategy for pathological conditions characterised by altered bone homeostasis, including osteoporosis. We investigated a library of compounds (4-13) exhibiting different degrees of chemical similarity with three indole derivatives (1-3), which have been recently identified by us as PAMs of the A2B AR able to promote mesenchymal stem cell differentiation and bone formation. Evaluation of mineralisation activity of 4-13 in the presence and in the absence of the agonist BAY60-6583 allowed the identification of lead compounds with therapeutic potential as anti-osteoporosis agents. Further biological characterisation of one of the most performing compounds, the benzofurane derivative 9, confirmed that such a molecule behaves as PAM of the A2B AR
Augmented Reality, Virtual Reality and Artificial Intelligence in Orthopedic Surgery: A Systematic Review
Background: The application of virtual and augmented reality technologies to orthopaedic surgery training and practice aims to increase the safety and accuracy of procedures and reducing complications and costs. The purpose of this systematic review is to summarise the present literature on this topic while providing a detailed analysis of current flaws and benefits. Methods: A comprehensive search on the PubMed, Cochrane, CINAHL, and Embase database was conducted from inception to February 2021. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were used to improve the reporting of the review. The Cochrane Risk of Bias Tool and the Methodological Index for Non-Randomized Studies (MINORS) was used to assess the quality and potential bias of the included randomized and non-randomized control trials, respectively. Results: Virtual reality has been proven revolutionary for both resident training and preoperative planning. Thanks to augmented reality, orthopaedic surgeons could carry out procedures faster and more accurately, improving overall safety. Artificial intelligence (AI) is a promising technology with limitless potential, but, nowadays, its use in orthopaedic surgery is limited to preoperative diagnosis. Conclusions: Extended reality technologies have the potential to reform orthopaedic training and practice, providing an opportunity for unidirectional growth towards a patient-centred approach
Human papillomavirus (HPV) genotypes among HIV-infected and HIV-uninfected women in Mozambique
Optical Frequency Link between Torino and Firenze for remote comparison between Yb and Sr optical clocks
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