851 resultados para Human body--Philosophy.
Resumo:
Perhaps the greatest barrier to development of the field of transmembrane drug delivery is that only a limited number of drugs are amenable to administration by this route. The highly lipophilic nature and barrier function of the uppermost layer of the skin, the stratum corneum, for example, restricts the permeation of hydrophilic, high molecular weight and charged compounds into the systemic circulation. Other membranes in the human body can also present significant barriers to drug permeation. In order to successfully deliver hydrophilic drugs, and macromolecular agents of interest, including peptides, DNA and small interfering RNA, many research groups and pharmaceutical companies Worldwide are focusing on the use of microporation methods and devices. Whilst there are a variety of microporation techniques, including the use of laser, thermal ablation, electroporation, radiofrequency, ultrasound, high pressure jets, and microneedle technology, they share the common goal of enhancing the permeability of a biological membrane through the creation of transient aqueous transport pathways of micron dimensions across that membrane. Once created, these micropores are orders of magnitude larger than molecular dimensions and, therefore, should readily permit the transport of hydrophilic macromolecules. Additionally, microporation devices also enable minimally-invasive sampling and monitoring of biological fluids. This review deals with the innovations relating to microporation-based methods and devices for drug delivery and minimally invasive monitoring, as disclosed in recent patent literature. © 2010 Bentham Science Publishers Ltd.
Resumo:
Adenosine is a ubiquitous molecule present in every cell of the human body. It has a wide range of physiological functions mediated predominantly through specific cell surface adenosine receptors. Adenosine has both pro- and anti-inflammatory effects and acts on inflammatory and resident immune cells and antioxidant enzymes. The elevation of adenosine in the bronchoalveolar lavage (BAL) fluid of asthmatics combined with its bronchoconstrictor effect on the airways in asthmatics has led to increased research into the contribution of adenosine in the pathophysiology of inflammation and asthma. This review looks at the airway response to adenosine and at the interaction of adenosine with mast cells and basophils.
Resumo:
The concept of a body-to-body network, where smart communicating devices carried or worn by a person are used to form a wireless network with devices situated on other nearby persons. New innovations in this area will see the form factor of smart devices being modified, so that they may be worn on the human body or integrated into clothing, in the process creating a new generation of smart people. Applications of body-to-body networking will extend well beyond the support of cellular and Wi-Fi networks. They will also be used in short-range covert military applications, first responder applications, team sports and used to interconnect body area networks (BAN). Security will be a major issue as routing between multiple nodes will increase the risk of unauthorized access and compromise sensitive data. This will add complexity to the medium access layer (MAC) and network management. Antennas designed to operate in body centric communications systems may be broadly categorized as on- or off-body radiators, according to their radiation pattern characteristics when mounted on the human body.
Resumo:
A vaginally-worn temperature telemeter may be used by women to chart their basal body temperature for ovulation detection. The telemeter uses a temperature to pulse width converter to key a Colpitts oscillator which is controlled in frequency by a 418 MHz SAW resonator. The circuit’s tank inductor acts as a compact, multi-turn loop antenna with a radiated power in isolation of around 1 uW. The transmission characteristics of the system are affected by the proximity of the human body, which acts as an electrically-large lossy dielectric. The RF link-budget must allow for the reduction in total emitted power, directional body-induced fading, and polarization effects. The polar power patterns of the telemeter were measured for both isolated and in-situ cases, using horizontal and vertical polarization. The power patterns were numerically integrated to determine relative emitted power, and a reference dipole used to determine the emitted power for the isolated device. In isolation the telemeter radiation is vertically polarized and isotropic in nature. With the telemeter in-situ, total body absorption was found to be over 20 dB, with directional fades of up to 40 dB; there was extensive cross-polarization, with up to 60% of radiated power horizontally polarized. With limited radiated power and directional fading, the operating range for the telemeter is limited to single room operation (less than 10m). The majority of RF radiation is absorbed by the body, but the radiation hazard is negligible due to the low power level of the device. The high level of cross-polarization suggests that either horizontal or vertically polarized base-station antennas may be used.
Resumo:
We address the problem of non-linearity in 2D Shape modelling of a particular articulated object: the human body. This issue is partially resolved by applying a different Point Distribution Model (PDM) depending on the viewpoint. The remaining non-linearity is solved by using Gaussian Mixture Models (GMM). A dynamic-based clustering is proposed and carried out in the Pose Eigenspace. A fundamental question when clustering is to determine the optimal number of clusters. From our point of view, the main aspect to be evaluated is the mean gaussianity. This partitioning is then used to fit a GMM to each one of the view-based PDM, derived from a database of Silhouettes and Skeletons. Dynamic correspondences are then obtained between gaussian models of the 4 mixtures. Finally, we compare this approach with other two methods we previously developed to cope with non-linearity: Nearest Neighbor (NN) Classifier and Independent Component Analysis (ICA).
Resumo:
The range of potential applications for indoor and campus based personnel localisation has led researchers to create a wide spectrum of different algorithmic approaches and systems. However, the majority of the proposed systems overlook the unique radio environment presented by the human body leading to systematic errors and inaccuracies when deployed in this context. In this paper RSSI-based Monte Carlo Localisation was implemented using commercial 868 MHz off the shelf hardware and empirical data was gathered across a relatively large number of scenarios within a single indoor office environment. This data showed that the body shadowing effect caused by the human body introduced path skew into location estimates. It was also shown that, by using two body-worn nodes in concert, the effect of body shadowing can be mitigated by averaging the estimated position of the two nodes worn on either side of the body. © Springer Science+Business Media, LLC 2012.
Resumo:
Wearable antenna performance measurements were used to characterize a synthetic variable layered phantom testbed, representative of human tissue for operation in the 868/915 MHz, and 2400 MHz industrial, scientific and medical frequency bands. Antenna radiation efficiency measurements on the phantom were compared with measurements on the thorax region of a human test subject. The results show that the phantom is representative of the human body for the application of wireless vital sign monitors, where conductive connections are made to the tissue.
Resumo:
This paper presents the results of a measurement campaign aimed at characterizing and modeling the indoor radio channel between two hypothetical cellular handsets. The device-to-device channel measurements were made at 868 MHz and investigated a number of different everyday scenarios such as the devices being held at the user's heads, placed in a pocket and one of the devices placed on a desktop. The recently proposed shadowed k-μ fading model was used to characterize these channels and was shown to provide a good description of the measured data. It was also evident from the experiments, that the device-to-device communications channel is susceptible to shadowing caused by the human body.
Resumo:
In this paper we investigate the first and second order characteristics of the received signal at the output ofhypothetical selection, equal gain and maximal ratio combiners which utilize spatially separated antennas at the basestation. Considering a range of human body movements, we model the model the small-scale fading characteristics ofthe signal using diversity specific analytical equations which take into account the number of available signal branchesat the receiver. It is shown that these equations provide an excellent fit to the measured channel data. Furthermore, formany hypothetical diversity receiver configurations, the Nakagami-m parameter was found to be close to 1.
Resumo:
In this paper, the results of radio channel measurements between two hypothetical cellular handsets in an outdoor urban environment are reported. The device-to-device channel measurements were made at 868 MHz and investigated a number of different everyday usage scenarios such as the devices being held at the user's heads, placed in a pocket while one of the users rotated or both moved randomly. It was found that shadowing of the main signal path caused by the human body will be an important factor in future device-to-device communications at this frequency. The recently proposed shadowed κ-μ fading model was used to characterize these channels and shown to provide a good description of the measured data.
Resumo:
In this paper, a number of off-body channels which are susceptible to shadowing caused by the human body are investigated. In particular, the recently proposed shadowed κ–μ fading model is fitted to data obtained from field trials performed in low multipath conditions at 2.45 GHz. It is shown that this model provides a significantly improved fit to off-body channels which are subject to shadowing when compared to other fading models such as lognormal, Nakagami-m and Rice which are commonly applied to model fading in body centric communications channels.
Resumo:
Anatomy and physiology refers to the structure and function of the human body. Students studying this module, known as life science or bioscience, develop knowledge of the structure (anatomy) and function (physiology) of the body that can be applied in clinical practice and support other study courses.
Resumo:
Human occupants within indoor environments are not always stationary and their movement will lead to temporal channel variations that strongly affect the quality of indoor wireless communication systems. This paper describes a statistical channel characterization, based on experimental measurements, of human body effects on line-of-sight indoor narrowband propagation at 5.2 GHz. The analysis shows that, as the number of pedestrians within the measurement location increases, the Ricean K-factor that best fits the empirical data tends to decrease proportionally, ranging from K=7 with 1 pedestrian to K=0 with 4 pedestrians. Level crossing rate results were Rice distributed, while average fade duration results were significantly higher than theoretically computed Rice and Rayleigh, due to the fades caused by pedestrians. A novel CDF that accurately characterizes the 5.2 GHz channel in the considered indoor environment is proposed. For the first time, the received envelope CDF is explicitly described in terms of a quantitative measurement of pedestrian traffic within the indoor environment.
Resumo:
Blending Art and Science in Nurse Education: The Benefits and Impact of Creative Partnerships
This paper presents the benefits of an innovative education partnership between lecturers from the School of Nursing and Midwifery, Queens University Belfast and Arts Care, a unique Arts and Health Charity in Northern Ireland, to engage nursing students in life sciences
Nursing and Midwifery students often struggle to engage with life science modules because they lack confidence in their ability to study science.This project was funded by a Teaching Innovation Award from the School of Nursing and Midwifery, Queens University Belfast, to explore creative ways of engaging year one undergraduate nursing students in learning anatomy and physiology. The project was facilitated through collaboration between Teaching staff from the School of Nursing and Midwifery and Arts Care, Northern Ireland. This unique Arts and Health Charity believes in the benefits of creativity to well being.
RESEARCH OBJECTIVE(S)
To explore creative ways of engaging year one undergraduate nursing students in learning anatomy and physiology.
METHODS AND METHODLOGY
Students participated in a series of workshops designed to explore the cells, tissues and organs of the human body through the medium of felt. Facilitated by an Arts Care artist, and following self-directed preparation, students discussed and translated their learning of the cells, tissues and organs of the human body into striking felt images. During the project students kept a reflective journal of their experience to document how participation in the project enhanced their learning and professional development
RESULTS
Creativity transformed and brought to life the students learning of the cells, tissues and organs of the human body.
The project culminated in the exhibition of a unique body of artwork which has been exhibited across Northern Ireland in hospitals and galleries and viewed by fellow students, teaching staff, nurses from practice, artists, friends, family and members of the public.
CONCLUSION
The impact of creativity learning strategies in nurse education should be further explored.
REFERENCES
Bennett, M and Rogers, K.MA. (2014) First impressions matter: an active, innovative and engaging method to recruit student volunteers for a pedagogic project. Reflections, Available online at: QUB, Centre for Educational Development / Publications / Reflections Newsletter, Issue 18, June 2014.
Chickering,A.W. and Gamson,Z.F. (1987) Seven principles for good practice in undergraduate education The American Association for Higher Education Bulletin, March. http://www.aahea.org/aahea/articles/sevenprinciples1987.htm, accessed 8th August 2014
Fell, P., Borland, G., Lynne, V. (2012) Lab versus lectures: can lab based practical sessions improve nursing students’ learning of bioscience? Health and Social Care Education 3:1, 33-38
Resumo:
There is an increasing interest in the biomedical field to create implantable medical devices to provide a temporary mechanical function for use inside the human body. In many of these applications bioresorbable polymer composites using PLLA with β-TCP , are increasingly being used due to their biocompatability, biodegradability and mechanical strength.1,3 These medical devices can be manufactured using conventional plastics processing methods such as injection moulding and extrusion, however there is great need to understand and control the process due to a lack of knowledge on the influence of processing on material properties. With the addition of biocompatible additives there is also a requirement to be able to predict the quality and level of dispersion within the polymer matrix. On-line UV-Vis spectroscopy has been shown to monitor the quality of fillers in polymers. This can eliminate time consuming and costly post-process evaluation of additive dispersion. The aim of this work was to identify process and performance relationships of PLLA/β-TCP composites with respect to melt-extrusion conditions. This is part of a wider study into on-line process monitoring of bioresorbable polymers as used in the medical industry.
These results show that final properties of the PLLA/ β-TCP composite are highly influenced by the particle size and loading. UV-Vis spectroscopy can be used on-line to monitor the final product and this can be utilised as a valuable tool for quality control in an application where consistent performance is of paramount importance.