903 resultados para medical optics and biotechnology


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Historians of medicine, childhood, and paediatrics, have often assumed that early modern doctors neither treated children, nor adapted their medicines to suit the peculiar temperaments of the young. Through an examination of medical textbooks and doctors’ casebooks, this article refutes these assumptions. It argues that medical authors and practising doctors regularly treated children, and were careful to tailor their remedies to complement the distinctive constitutions of children. Thus, this article proposes that a concept of ‘children’s physic’ existed in early modern England: this term refers to the notion that children were physiologically distinct, requiring special medical care. Children’s physic was rooted in the ancient traditions of Hippocratic and Galenic medicine: it was the child’s humoral makeup that underpinned all medical ideas about children’s bodies, minds, diseases, and treatments. Children abounded in the humour blood, which made them humid and weak, and in need of medicines of a particularly gentle nature.

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Background: Studies evaluating acceptability of simplified follow-up after medical abortion have focused on high-resource or urban settings where telephones, road connections, and modes of transport are available and where women have formal education. Objective: To investigate women's acceptability of home-assessment of abortion and whether acceptability of medical abortion differs by in-clinic or home-assessment of abortion outcome in a low-resource setting in India. Design: Secondary outcome of a randomised, controlled, non-inferiority trial. Setting Outpatient primary health care clinics in rural and urban Rajasthan, India. Population: Women were eligible if they sought abortion with a gestation up to 9 weeks, lived within defined study area and agreed to follow-up. Women were ineligible if they had known contraindications to medical abortion, haemoglobin < 85mg/l and were below 18 years. Methods: Abortion outcome assessment through routine clinic follow-up by a doctor was compared with home-assessment using a low-sensitivity pregnancy test and a pictorial instruction sheet. A computerized random number generator generated the randomisation sequence (1: 1) in blocks of six. Research assistants randomly allocated eligible women who opted for medical abortion (mifepristone and misoprostol), using opaque sealed envelopes. Blinding during outcome assessment was not possible. Main outcome measures: Women's acceptability of home-assessment was measured as future preference of follow-up. Overall satisfaction, expectations, and comparison with previous abortion experiences were compared between study groups. Results: 731 women were randomized to the clinic follow-up group (n = 353) or home-assessment group (n = 378). 623 (85%) women were successfully followed up, of those 597 (96%) were satisfied and 592 (95%) found the abortion better or as expected, with no difference between study groups. The majority, 355 (57%) women, preferred home-assessment in the event of a future abortion. Significantly more women, 284 (82%), in the home-assessment group preferred home-assessment in the future, as compared with 188 (70%) of women in the clinic follow-up group, who preferred clinic follow-up in the future (p < 0.001). Conclusion: Home-assessment is highly acceptable among women in low-resource, and rural, settings. The choice to follow-up an early medical abortion according to women's preference should be offered to foster women's reproductive autonomy.

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Frequent advances in medical technologies have brought fonh many innovative treatments that allow medical teams to treal many patients with grave illness and serious trauma who would have died only a few years earlier. These changes have given some patients a second chance at life, but for others. these new treatments have merely prolonged their dying. Instead of dying relatively painlessly, these unfortunate patients often suffer from painful tenninal illnesses or exist in a comatose state that robs them of their dignity, since they cannot survive without advanced and often dehumanizing forms of treatment. Due to many of these concerns, euthanasia has become a central issue in medical ethics. Additionally, the debate is impacted by those who believe that patients have the right make choices about the method and timing of their deaths. Euthanasia is defined as a deliberate act by a physician to hasten the death of a patient, whether through active methods such as an injection of morphine, or through the withdrawal of advanced forms of medical care, for reasons of mercy because of a medical condition that they have. This study explores the question of whether euthanasia is an ethical practice and, as determined by ethical theories and professional codes of ethics, whether the physician is allowed to provide the means to give the patient a path to a "good death," rather than one filled with physical and mental suffering. The paper also asks if there is a relevant moral difference between the active and passive forms of euthanasia and seeks to define requirements to ensure fully voluntary decision making through an evaluation of the factors necessary to produce fully informed consent. Additionally, the proper treatments for patients who suffer from painful terminal illnesses, those who exist in persistent vegetative states and infants born with many diverse medical problems are examined. The ultimate conclusions that are reached in the paper are that euthanasia is an ethical practice in certain specific circumstances for patients who have a very low quality of life due to pain, illness or serious mental deficits as a result of irreversible coma, persistent vegetative state or end-stage clinical dementia. This is defended by the fact that the rights of the patient to determine his or her own fate and to autonomously decide the way that he or she dies are paramount to all other factors in decisions of life and death. There are also circumstances where decisions can be made by health care teams in conjunction with the family to hasten the deaths of incompetent patients when continued existence is clearly not in their best interest, as is the case of infants who are born with serious physical anomalies, who are either 'born dying' or have no prospect for a life that is of a reasonable quality. I have rejected the distinction between active and passive methods of euthanasia and have instead chosen to focus on the intentions of the treating physician and the voluntary nature of the patient's request. When applied in equivalent circumstances, active and passive methods of euthanasia produce the same effects, and if the choice to hasten the death of the patient is ethical, then the use of either method can be accepted. The use of active methods of euthanasia and active forms of withdrawal of life support, such as the removal of a respirator are both conscious decisions to end the life of the patient and both bring death within a short period of time. It is false to maintain a distinction that believes that one is active killing. whereas the other form only allows nature to take it's course. Both are conscious choices to hasten the patient's death and should be evaluated as such. Additionally, through an examination of the Hippocratic Oath, and statements made by the American Medical Association and the American College of physicians, it can be shown that the ideals that the medical profession maintains and the respect for the interests of the patient that it holds allows the physician to give aid to patients who wish to choose death as an alternative to continued suffering. The physician is also allowed to and in some circumstances, is morally required, to help dying patients whether through active or passive forms of euthanasia or through assisted suicide. Euthanasia is a difficult topic to think about, but in the end, we should support the choice that respects the patient's autonomous choice or clear best interest and the respect that we have for their dignity and personal worth.

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OBJETIVO: Verificar a frequência de problemas médicos autorrelatados e a frequência de áreas de dor no corpo em pacientes com dor orofacial, comparando-os a pacientes submetidos a tratamento odontológico de rotina. MÉTODOS: Os dados foram coletados dos arquivos da Clínica de Dor Orofacial (Grupo A, n=319) e de clínicas de tratamento odontológico rotineiro (Grupo B, n=84) da Faculdade de Odontologia de Araraquara, São Paulo, Brasil. Os indivíduos responderam a questionários e preencheram um mapa corporal indicando os locais de dor. RESULTADOS: O teste de Mann-Whitney demonstrou que o Grupo A apresentou uma média de relatos de problemas médicos superior ao Grupo B (p=0,004). Para ambos os grupos, o teste de correlação de Pearson demonstrou correlação positiva entre os problemas médicos e a frequência de áreas dolorosas (respectivamente, 0,478, p=0,001 e 0,246, p=0,000). CONCLUSÕES: O Grupo A relatou maior número de problemas médicos e houve correlação positiva entre a frequência desses problemas e a de áreas de dor para ambos os grupos.

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Due to shortage of time and limited availability of faculty surgeons to teach basic surgical skills during medical graduation, the search for alternative ways of simulated training with feedback is needed. The purpose of this study was to compare the simulated teaching of suture skills to novice medical students by senior medical students and by experienced faculty surgeons. Forty-eight novice medical students were randomly assigned to three practice conditions on bench model (n = 16): self-directed suture training (control), senior medical student-directed suture skills' training, or experienced faculty surgeon-directed suture skills' training. Pre- and post-tests were applied. Global Rating Scale with blinded evaluation and self-perceived confidence based on Likert scale were used to assess all suture performances in pre- and post-training. Effect size was also calculated. The analysis made after training showed that the students who received feedback from the instructors had better performance based on the Global Rating Scale (all p < 0.0000) and felt more confident to carry out sutures (all p < 0.0000) when compared to the control. There was no significant difference (all p > 0.05) between the student-directed teaching and faculty-directed teaching groups. The magnitude of the effect (instructor-directed training suture) was considered large (>0.80) in all measurements. The acquisition of suture skills after student-directed training was similar to the training supervised by faculty surgeon, and the increase in suture performances of trainees that received instructor administered training was superior to self-directed learning. © 2013 Springer-Verlag Italia.

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To compare the use of analgesia versus neonatologists' perception regarding analgesic use in painful procedures in the years 2001, 2006, and 2011. This was a prospective cohort study of all newborns admitted to four university neonatal intensive care units (NICUs) during one month in 2001, 2006, and 2011. The frequency of analgesic prescription for painful procedures was evaluated. Of the 202 neonatologists, 188 answered a questionnaire giving their opinion on the intensity of pain during lumbar puncture (LP), tracheal intubation, mechanical ventilation (MV), and postoperative period (PO) using a 10-cm visual analogic scale (VAS; pain >3cm). For LP, 12% (2001), 43% (2006), and 36% (2011) were performed using analgesia. Among the neonatologists, 40-50% reported VAS >3 for LP in all study periods. For intubation, 30% received analgesia in the study periods, and 35% (2001), 55% (2006), and 73% (2011) of the neonatologists reported VAS >3 and would prescribe analgesia for this procedure. As for MV, 45% (2001), 64% (2006), and 48% (2011) of patient-days were under analgesia; 56% (2001), 57% (2006), and 26% (2011) of neonatologists reported VAS >3 and said they would use analgesia during MV. For the first three PO days, 37% (2001), 78% (2006), and 89% (2011) of the patients received analgesia and more than 90% of neonatologists reported VAS >3 for major surgeries. Despite an increase in the medical perception of neonatal pain and in analgesic use during painful procedures, the gap between clinical practice and neonatologist perception of analgesia need did not change during the ten-year period.

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PURPOSE: This study describes in Brazil and in the global biomedical community the time course of the development of animal research welfare guidelines. METHODS: The database of the Ethics Committee of the Faculty of Medicine of Ribeirao Preto (EC/FMRP-USP), Brazil, was surveyed since its inception in 2002 as the regulations became more stringent to provide better protection of animal research welfare at this institution. Medline database was evaluated to identify the number of publications in the period between 1968 and 2008 that used research animals and were in compliance with established ethics guidelines. RESULTS: The EC/FMRP-USP evaluated 979 projects up until 2009. Most of the applications came from Department of Physiology and the most frequently requested species was the rat. In 2004, national research funding agencies started to request prior approval from institutional review ethics committees prior to application review and this requirement became federal law in Brazil in 2008. The analysis of international publications revealed a relative reduction in studies involving research animals (18% in 1968 to 7.5% in 2008). CONCLUSIONS: The present work showed that in the last four decades major changes occurred in the guidelines dictating use of research animals occurred and they are being adopted by developing countries. Moreover, animal welfare concern in the scientific community preceded the introduction of journal guidelines for this purpose. Furthermore, in Brazil it was anticipated that laws were needed to protect animal research welfare from being not upheld.

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Objectives: Several clinical trials conducted in Europe and US reported favorable outcomes of patients with APL treated with the combination of all trans retinoic acid (ATRA) and anthracyclines. Nevertheless, the results observed in developing countries with the same regimen was poorer, mainly due to high early mortality mainly due bleeding. The International Consortium on Acute Promyelocytic Leukemia (IC-APL) is an initiative of the International Members Committee of the ASH and the project aims to reduce this gap through the establishment of international network, which was launched in Brazil, Mexico and Uruguay. Methods: The IC-APL treatment protocol is similar to the PETHEMA 2005, but changing idarubicin to daunorubicin. All patients with a suspected diagnosis of APL were immediately started on ATRA, while bone marrow samples were shipped to a national central lab where genetic verification of the diagnosis was performed. The immunofluorescence using an anti-PML antibody allowed a rapid confirmation of the diagnosis and, the importance of supportive measures was reinforced. Results: The interim analysis of 97 patients enrolled in the IC-APL protocol showed that complete remission (CR) rate was 83% and the 2-year overall survival and disease-free survival were 80% and 90%, respectively. Of note, the early mortality rate was reduced to 7.5%. Discussion: The results of IC-APL demonstrate the impact of educational programs and networking on the improvement of the leukemia treatment outcome in developing countries.

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PURPOSE: This study describes in Brazil and in the global biomedical community the time course of the development of animal research welfare guidelines. METHODS: The database of the Ethics Committee of the Faculty of Medicine of Ribeirao Preto (EC/FMRP-USP), Brazil, was surveyed since its inception in 2002 as the regulations became more stringent to provide better protection of animal research welfare at this institution. Medline database was evaluated to identify the number of publications in the period between 1968 and 2008 that used research animals and were in compliance with established ethics guidelines. RESULTS: The EC/FMRP-USP evaluated 979 projects up until 2009. Most of the applications came from Department of Physiology and the most frequently requested species was the rat. In 2004, national research funding agencies started to request prior approval from institutional review ethics committees prior to application review and this requirement became federal law in Brazil in 2008. The analysis of international publications revealed a relative reduction in studies involving research animals (18% in 1968 to 7.5% in 2008). CONCLUSIONS: The present work showed that in the last four decades major changes occurred in the guidelines dictating use of research animals occurred and they are being adopted by developing countries. Moreover, animal welfare concern in the scientific community preceded the introduction of journal guidelines for this purpose. Furthermore, in Brazil it was anticipated that laws were needed to protect animal research welfare from being not upheld.

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The hydrogen production in the green microalga Chlamydomonas reinhardtii was evaluated by means of a detailed physiological and biotechnological study. First, a wide screening of the hydrogen productivity was done on 22 strains of C. reinhardtii, most of which mutated at the level of the D1 protein. The screening revealed for the first time that mutations upon the D1 protein may result on an increased hydrogen production. Indeed, productions ranged between 0 and more than 500 mL hydrogen per liter of culture (Torzillo, Scoma et al., 2007a), the highest producer (L159I-N230Y) being up to 5 times more performant than the strain cc124 widely adopted in literature (Torzillo, Scoma, et al., 2007b). Improved productivities by D1 protein mutants were generally a result of high photosynthetic capabilities counteracted by high respiration rates. Optimization of culture conditions were addressed according to the results of the physiological study of selected strains. In a first step, the photobioreactor (PBR) was provided with a multiple-impeller stirring system designed, developed and tested by us, using the strain cc124. It was found that the impeller system was effectively able to induce regular and turbulent mixing, which led to improved photosynthetic yields by means of light/dark cycles. Moreover, improved mixing regime sustained higher respiration rates, compared to what obtained with the commonly used stir bar mixing system. As far as the results of the initial screening phase are considered, both these factors are relevant to the hydrogen production. Indeed, very high energy conversion efficiencies (light to hydrogen) were obtained with the impeller device, prooving that our PBR was a good tool to both improve and study photosynthetic processes (Giannelli, Scoma et al., 2009). In the second part of the optimization, an accurate analysis of all the positive features of the high performance strain L159I-N230Y pointed out, respect to the WT, it has: (1) a larger chlorophyll optical cross-section; (2) a higher electron transfer rate by PSII; (3) a higher respiration rate; (4) a higher efficiency of utilization of the hydrogenase; (5) a higher starch synthesis capability; (6) a higher per cell D1 protein amount; (7) a higher zeaxanthin synthesis capability (Torzillo, Scoma et al., 2009). These information were gathered with those obtained with the impeller mixing device to find out the best culture conditions to optimize productivity with strain L159I-N230Y. The main aim was to sustain as long as possible the direct PSII contribution, which leads to hydrogen production without net CO2 release. Finally, an outstanding maximum rate of 11.1 ± 1.0 mL/L/h was reached and maintained for 21.8 ± 7.7 hours, when the effective photochemical efficiency of PSII (ΔF/F'm) underwent a last drop to zero. If expressed in terms of chl (24.0 ± 2.2 µmoles/mg chl/h), these rates of production are 4 times higher than what reported in literature to date (Scoma et al., 2010a submitted). DCMU addition experiments confirmed the key role played by PSII in sustaining such rates. On the other hand, experiments carried out in similar conditions with the control strain cc124 showed an improved final productivity, but no constant PSII direct contribution. These results showed that, aside from fermentation processes, if proper conditions are supplied to selected strains, hydrogen production can be substantially enhanced by means of biophotolysis. A last study on the physiology of the process was carried out with the mutant IL. Although able to express and very efficiently utilize the hydrogenase enzyme, this strain was unable to produce hydrogen when sulfur deprived. However, in a specific set of experiments this goal was finally reached, pointing out that other than (1) a state 1-2 transition of the photosynthetic apparatus, (2) starch storage and (3) anaerobiosis establishment, a timely transition to the hydrogen production is also needed in sulfur deprivation to induce the process before energy reserves are driven towards other processes necessary for the survival of the cell. This information turned out to be crucial when moving outdoor for the hydrogen production in a tubular horizontal 50-liter PBR under sunlight radiation. First attempts with laboratory grown cultures showed that no hydrogen production under sulfur starvation can be induced if a previous adaptation of the culture is not pursued outdoor. Indeed, in these conditions the hydrogen production under direct sunlight radiation with C. reinhardtii was finally achieved for the first time in literature (Scoma et al., 2010b submitted). Experiments were also made to optimize productivity in outdoor conditions, with respect to the light dilution within the culture layers. Finally, a brief study of the anaerobic metabolism of C. reinhardtii during hydrogen oxidation has been carried out. This study represents a good integration to the understanding of the complex interplay of pathways that operate concomitantly in this microalga.

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In questo elaborato si affrontano problematiche cliniche legate ai traumi gravi della cute in cui è necessario intervenire chirurgicamente per ripristinare una situazione normale: si approfondisce lo studio della fisiologia del tessuto, la classificazione dei gradi delle ustioni della pelle, la guarigione delle ferite e la meccanica della cute. Il trapianto di tessuto autologo costituisce la soluzione più efficace e con minori complicazioni. Tuttavia il paziente potrebbe non presentare una superficie di cute disponibile sufficientemente estesa, per cui si ricorre ad altri metodi. In primo luogo, si effettuano degli allotrapianti di tessuto di donatore cadavere prelevati secondo le normative vigenti e conservati attraverso le varie tecniche, il cui sviluppo ha consentito una durata di conservazione maggiore; mentre la glicerolizzazione abbatte al 100% il rischio di trasmissione di patologie e lo sviluppo di microorganismi, la crioconservazione preserva la vitalità del tessuto. La chirurgia utilizzata per queste operazioni si avvale di tecnologie innovative come la Tecnologia a Pressione Negativa. Un'alternativa necessaria per sopperire all'ingente richiesta di tessuto di donatore sono i sostituti cutanei, che presentano un grande potenziale per il futuro. Per eliminare totalmente il rischio di rigetto sarebbe necessario personalizzare il costrutto utilizzando cellule autologhe, ma la ricerca è stata rallentata da minori investimenti da parte dell'industria biomedica, che si è maggiormente focalizzata sulla realizzazione di prodotti utilizzabili da un più ampio raggio di pazienti. Per queste ragioni, l'ingegneria tissutale della cute ha trovato più ampio campo di applicazione nel sistema dei test in vitro. A tale scopo sono stati creati dei protocolli certificati per testare la corrosività, la irritabilità e la vitalità del tessuto cutaneo, quali EpiDerm, EpiSkin e SkinEthic che si avvalgono dell'uso del metodo MMT e della spettrofotometria, che è diventata un supporto fondamentale per le scienze biologiche.

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This thesis reports on the experimental realization, characterization and application of a novel microresonator design. The so-called “bottle microresonator” sustains whispering-gallery modes in which light fields are confined near the surface of the micron-sized silica structure by continuous total internal reflection. While whispering-gallery mode resonators in general exhibit outstanding properties in terms of both temporal and spatial confinement of light fields, their monolithic design makes tuning of their resonance frequency difficult. This impedes their use, e.g., in cavity quantum electrodynamics (CQED) experiments, which investigate the interaction of single quantum mechanical emitters of predetermined resonance frequency with a cavity mode. In contrast, the highly prolate shape of the bottle microresonators gives rise to a customizable mode structure, enabling full tunability. The thesis is organized as follows: In chapter I, I give a brief overview of different types of optical microresonators. Important quantities, such as the quality factor Q and the mode volume V, which characterize the temporal and spatial confinement of the light field are introduced. In chapter II, a wave equation calculation of the modes of a bottle microresonator is presented. The intensity distribution of different bottle modes is derived and their mode volume is calculated. A brief description of light propagation in ultra-thin optical fibers, which are used to couple light into and out of bottle modes, is given as well. The chapter concludes with a presentation of the fabrication techniques of both structures. Chapter III presents experimental results on highly efficient, nearly lossless coupling of light into bottle modes as well as their spatial and spectral characterization. Ultra-high intrinsic quality factors exceeding 360 million as well as full tunability are demonstrated. In chapter IV, the bottle microresonator in add-drop configuration, i.e., with two ultra-thin fibers coupled to one bottle mode, is discussed. The highly efficient, nearly lossless coupling characteristics of each fiber combined with the resonator's high intrinsic quality factor, enable resonant power transfers between both fibers with efficiencies exceeding 90%. Moreover, the favorable ratio of absorption and the nonlinear refractive index of silica yields optical Kerr bistability at record low powers on the order of 50 µW. Combined with the add-drop configuration, this allows one to route optical signals between the outputs of both ultra-thin fibers, simply by varying the input power, thereby enabling applications in all-optical signal processing. Finally, in chapter V, I discuss the potential of the bottle microresonator for CQED experiments with single atoms. Its Q/V-ratio, which determines the ratio of the atom-cavity coupling rate to the dissipative rates of the subsystems, aligns with the values obtained for state-of-the-art CQED microresonators. In combination with its full tunability and the possibility of highly efficient light transfer to and from the bottle mode, this makes the bottle microresonator a unique tool for quantum optics applications.

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In Switzerland and in the whole western world, the growing popularity of CAM is calling for its implementation in the undergraduate medical curriculum.