Very-low-carbohydrate diets or ketogenic diets have been in use since the 1920s as a therapy for epilepsy and can, in some cases, completely remove the need for medication. From the 1960s onwards ...they have become widely known as one of the most common methods for obesity treatment. Recent work over the last decade or so has provided evidence of the therapeutic potential of ketogenic diets in many pathological conditions, such as diabetes, polycystic ovary syndrome, acne, neurological diseases, cancer and the amelioration of respiratory and cardiovascular disease risk factors. The possibility that modifying food intake can be useful for reducing or eliminating pharmaceutical methods of treatment, which are often lifelong with significant side effects, calls for serious investigation. This review revisits the meaning of physiological ketosis in the light of this evidence and considers possible mechanisms for the therapeutic actions of the ketogenic diet on different diseases. The present review also questions whether there are still some preconceived ideas about ketogenic diets, which may be presenting unnecessary barriers to their use as therapeutic tools in the physician's hand.
Ultrasound has become a widely used diagnostic technique. While its role in patient evaluation is well known, its utility during preclinical courses such as anatomy and physiology is becoming ...increasingly recognized. The aim of the present study was to assess the feasibility/utility of integrating ultrasound-based sessions into conventional undergraduate medical school programs of physiology of the cardiovascular system and cardiovascular reflexes and to evaluate student perceptions of an ultrasound-based didactic session. Second-year medical students enrolled in the University of Padova attended a didactic session during which basic concepts regarding ultrasound instrumentation, image production, and spatial orientation were presented. Five anatomic sectors (the heart, aorta, neck vessels, inferior vena cava, and femoral veins) were then examined on a volunteer. Student perceptions of the images that were projected, the usefulness of the presentation, and the reproducibility of the experience were assessed at the end of the lecture with an anonymous questionnaire consisting of positive and negative items that were rated using a 5-point Likert scale and with two questions. One hundred eleven students attended the lecture; 99% of them found it very interesting, and none considered it boring or a waste of time. More than 96% thought it helped them to gain a better comprehension of the subject and would recommend it to a colleague. In conclusion, as ultrasound has been found to be a valuable resource for the teaching of physiology of the cardiovascular system and cardiovascular reflexes, efforts should be made to integrate ultrasound sessions into the traditional human physiology curriculum.
Phenotypic intermediacy is an indicator of putative hybrid origin and has provided the main clues to discovering hybrid plants in nature. Mandevilla pentlandiana and M. laxa (Apocynaceae) are sister ...species with clear differences in floral phenotype and associated pollinator guilds: diurnal Hymenoptera and nocturnal hawkmoths, respectively. The presence of individuals with intermediate phenotypes in a wild population raises questions about the roles of visual and olfactory signals (i.e. corolla morphology and floral fragrances) as barriers to interbreeding, and how the breakdown of floral isolation occurs. We examined phenotypic variation in a mixed Mandevilla population, analysing the chemical composition of floral fragrances, characterising floral shape through geometric morphometrics and assessing individual grouping through taxonomically relevant traits and an unsupervised learning algorithm. We quantified the visitation frequencies of floral visitors and tracked their foraging movements using pollen analogues. The presence of morphologically intermediate individuals and pollen analogue movement suggested extensive hybridisation between M. laxa and M. pentlandiana, along with asymmetrical rates of backcrossing between these putative hybrids and M. laxa. Floral volatiles from putative hybrid individuals showed a transgressive phenotype, with additional compounds not emitted by either parental species. Our results suggest the presence of a hybrid swarm between sympatric M. pentlandiana and M. laxa and indicate that initial hybridisation events between these parental species are rare, but once they occur, visits between putative hybrids and M. laxa are common and facilitate continued introgression.
Canada has incrementally reduced restrictions to blood and plasma donation that impact men who have sex with men, gay, bisexual, and queer men, and some Two Spirit, transgender and non-binary ...individuals (MSM/2SGBTQ+). Prior to the launch of a pilot program in 2021 enabling some MSM/2SGBTQ + to donate source plasma, we explored the acceptability of the program among individuals who could become eligible to donate in the program.
We invited men identifying as MSM/2SGBTQ + to participate in two consecutive semi-structured interviews to explore their views on blood and plasma donation policy, plasma donation, and the proposed Canadian plasma donation program. Interview transcripts were analyzed thematically and acceptability-related themes were mapped onto the Theoretical Framework of Acceptability.
Twenty-seven men identifying as having sex with men participated in 53 interviews. Eighteen themes were mapped onto the seven construct domains of the Theoretical Framework of Acceptability. Underlying all aspects of acceptability was a tension between four primary values influencing participants' views: altruism, equity, supply sufficiency, and evidence-based policy. The program was viewed as welcome progress on a discriminatory policy, with many excited to participate, yet tension with inequitable aspects of the program undermined support for the program and interest to contribute to it. The high demands of the program are unique for MSM/2SGBTQ + and are only tolerable as part of a program that is an incremental and instrumental step to more equitable donation policies.
Findings highlight past experiences of exclusion in Canada as a unique and critical part of the context of the donation experience among MSM/2SGBTQ+. Despite the program's goals of greater inclusivity of MSM/2SGBTQ + individuals, the anticipated experience of the program included continued stigmatization and inequities. Future research should seek to understand the experienced views of MSM/2SGBTQ + donors to ensure that as policies change, policies are implemented equitably.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ultrasound imaging is a useful diagnostic technique that has spread among several different medical specialties within the last few years. Initially restricted to radiology, cardiology, obstetrics, ...and gynecology, today it is widely used by many specialists, especially in critical care. New graduate physicians will need to be comfortable with ultrasound technologies and competent in the interpretation of ultrasound images for the well-being of patients, so the ultrasound technique has been included in current clinical teaching to medical students at university, but most of the time only by showing images or videos, without adding practical activities. The goals of the authors were to integrate chest ultrasound into the traditional teaching of the respiratory system physiology and to evaluate if it was possible, in terms of practicality and time spent. In November 2013, at the end of the course in human physiology, third-year medical students attended an ultrasound-integrated lecture at the Medical University of Padova (Padova, Italy). All students had previously passed the human anatomy exam, taken during the second academic year. The lectures were delivered by an expert sonographer physician (M. Paganini) supported by the professor (A. Rubini) of human physiology. Each lecture lasted 45 min and was divided into three parts. The lectures are discussed in this article.
The present study aimed to evaluate under controlled conditions the acquisition of
Hepatozoon canis by
Amblyomma ovale after feeding on infected dogs, and the subsequent induction of infection in ...uninfected dogs that ingested the experimentally infected ticks. Two
H. canis naturally infected dogs were infested with
A. ovale adult ticks derived from an uninfected laboratory tick colony. After feeding, two
A. ovale females presented
H. canis oocysts in the hemolymph at the first and fourth days after removal of ticks from dogs. The oocysts had an average size of 244.34
μm
×
255.46
μm. Three uninfected dogs were fed with ticks previously fed on the infected dogs. Only one dog became infected 32 days after oral inoculation, presenting circulating gametocytes, parasitemia less than 1%, and positive PCR confirmed to be
H. canis by DNA sequencing. The results obtained indicated
A. ovale ticks as potential vector of
H. canis in rural areas of Brazil.
New Findings
What is the central question of this study?
The wall of the colon shows an anisotropic and non‐linear mechanical response, because of the distribution and mechanical properties of ...sub‐components. This study aimed to provide, by a coupled experimental and computational approach, a constitutive framework to interpret the mechanics of colonic tissues.
What is the main finding and its importance?
Tensile tests on tissue samples from pig colon were developed. The experimental data were processed to define proper constitutive formulations. Constitutive parameters were identified by the inverse analysis of experimental tests. The reliability of parameters was assessed by agreement between the experimental and model results and the satisfaction of material thermomechanics principles. The developed constitutive framework is capable of interpreting the general anisotropic and non‐linear mechanical behaviour of colonic tissues.
The aim was to investigate the biomechanical behaviour of colonic tissues by a coupled experimental and numerical approach. The wall of the colon is composed of different tissue layers. Within each layer, different fibre families are distributed according to specific spatial orientations, which lead to a strongly anisotropic configuration. Accounting for the complex histology of the tissues, mechanical tests must be planned and designed to evaluate the behaviour of the colonic wall in different directions. Uni‐axial tensile tests were performed on tissue specimens from 15 fresh pig colons, accounting for six different loading directions (five specimens for each loading direction). The next step of the investigation was to define an appropriate constitutive framework and develop a procedure for identification of the constitutive parameters. A specific hyperelastic formulation was developed that accounted for the multilayered conformation of the colonic wall and the fibre‐reinforced configuration of the tissues. The parameters were identified by inverse analyses of the mechanical tests. The comparison of model results with experimental data, together with the evaluation of satisfaction of material thermomechanics principles, confirmed the reliability of the analysis developed. This work forms the basis for more comprehensive activities that aim to provide computational tools for the interpretation of surgical procedures that involve the gastrointestinal tract, considering the specific biomedical devices adopted.
Blood donation policy in Canada for gay, bisexual and other men who have had sex with men (gbMSM) has changed progressively in the last decade from indefinite deferral to 3-month deferral from last ...male-to-male sex. Driven by safety data and overseen by the national regulator, more inclusive policies continue to redress the disparity in donation for gbMSM. At the same time, the need for source plasma to prepare fractionated blood products is growing worldwide. The collection and processing of source plasma ensures greater safety compared to whole blood donation with respect to transfusion-transmitted infection. This greater safety offers an opportunity to evolve policies for gbMSM from time-based to behaviour-based deferral using revised eligibility criteria. However, changing policies does not in itself necessarily guarantee that gbMSM will donate or that staff in donor clinics are ready to support them to do so. In anticipation of a move to behaviour-based donation screening for gbMSM in Canada, we aim to assess the acceptability of and perceived barriers and enablers to source plasma donation using revised screening criteria for gbMSM among key stakeholders to inform policy implementation strategies. This mixed-methods feasibility study will involve gbMSM and donor centre staff to understand modifiable barriers to implementing more inclusive eligibility criteria. Key informant interviews and surveys will be rooted in the Theoretical Domains Framework to identify modifiable factors associated with source plasma donation motives in gbMSM and training needs in donation centre staff. We will use an integrated knowledge translation approach involving a partnership between researchers, the national blood operator and gbMSM, situating knowledge users as key research team members to ensure their perspectives inform all aspects of the research. Our integrated knowledge translation approach will provide a more comprehensive and collaborative understanding of blood operator and gbMSM needs while accelerating the implementation of study findings. Given the historical backdrop of the decades of exclusion of sexually active gbMSM from blood donation, this study has the potential not only to inform a process and policy for gbMSM to donate source plasma, a blood product, but also offers opportunities for new relationships between these knowledge users.
SuperAGILE: The hard X-ray imager for the AGILE space mission Feroci, M.; Costa, E.; Soffitta, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2007, Letnik:
581, Številka:
3
Journal Article
Recenzirano
SuperAGILE is a coded mask experiment based on silicon microstrip detectors. It operates in the 15–45
keV nominal energy range, providing crossed one-dimensional images of the X-ray sky with an ...on-axis angular resolution of 6
arcmin, over a field of view in excess of 1
sr. It was designed as the hard X-ray monitor of the AGILE space mission, a small satellite of the Italian Space Agency devoted to image the gamma-ray sky in the 30
MeV–50
GeV energy band. The AGILE mission was launched in a low-earth orbit on 23rd April 2007. In this paper we describe the SuperAGILE experiment, its construction and test processes, and its performance before flight, based on the on-ground test and calibrations.
A simplified model for the prediction of light extinction through combustion generated smoke is presented. The model builds upon existing theory and available experimental data to account for the ...principal factors that influence light extinction in participating media, including wavelength, primary particle size distribution and morphological structure of particle aggregation as well as multiple scattering among particles within a particle aggregation. Good agreement is demonstrated between the model predictions and experimental data in the visible and IR ranges. The model illustrates that as the mean particle size increases, the integral optical property of a soot cloud approaches that of monodisperse particles. It is postulated in the current study that the number of particles participating in multiple scattering is around 20 regardless of the real size of particle aggregation.
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