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We present results from an analysis of all data taken by the BICEP2, Keck Array, and BICEP3 CMB polarization experiments up to and including the 2018 observing season. We add additional Keck Array observations at 220 GHz and BICEP3 observations at 95 GHz to the previous 95/150/220 GHz dataset. The Q/U maps now reach depths of 2.8, 2.8, and 8.8 µK_{CMB} arcmin at 95, 150, and 220 GHz, respectively, over an effective area of ≈600 square degrees at 95 GHz and ≈400 square degrees at 150 and 220 GHz. The 220 GHz maps now achieve a signal-to-noise ratio on polarized dust emission exceeding that of Planck at 353 GHz. We take auto- and cross-spectra between these maps and publicly available WMAP and Planck maps at frequencies from 23 to 353 GHz and evaluate the joint likelihood of the spectra versus a multicomponent model of lensed ΛCDM+r+dust+synchrotron+noise. The foreground model has seven parameters, and no longer requires a prior on the frequency spectral index of the dust emission taken from measurements on other regions of the sky. This model is an adequate description of the data at the current noise levels. The likelihood analysis yields the constraint r_{0.05}<0.036 at 95% confidence. Running maximum likelihood search on simulations we obtain unbiased results and find that σ(r)=0.009. These are the strongest constraints to date on primordial gravitational waves.
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BACKGROUND: A pressing need exists to understand and optimize the use of dietary assessment tools that can be used in community-based participatory research (CBPR) interventions. A digital food record, which uses a mobile device to capture the dietary intake through text and photography inputs, is a particularly promising mobile assessment method. However, little is understood about the acceptability and feasibility of digital food records in CBPR and how to best tailor dietary assessment tools to the needs of a community. OBJECTIVE: The objective of our study was to evaluate the acceptability and feasibility of digital food records among church-based populations in resource-limited wards of Washington, DC, USA, using a mixed-methods approach. METHODS: This community-based pilot study was conducted as part of the Washington, DC Cardiovascular Health and Needs Assessment. Participants (n=17) received a mobile device (iPod Touch) to photodocument their dietary intake for a 3-day digital food record using a mobile app, FitNinja (Vibrent Health). The acceptability of the digital food record was explored through the thematic analysis of verbatim transcripts from a moderated focus group (n=8). In addition, the feasibility was evaluated by the percentage of participants complying with instructions (ie, capturing both before and after meal photos for at least 2 meals/day for 3 days). RESULTS: Qualitative themes identified were related to (1) the feasibility and acceptability of the mobile device and app, including issues in recording the dietary information and difficulty with photodocumentation; (2) suggestions for additional support and training experiences; and (3) comparisons with other mobile apps. Overall, the participants accepted the digital food record by demonstrating satisfaction with the tool and intent to continue the use (eg, participants recorded an average of 5.2, SD 7, consecutive days). Furthermore, of the 17 participants, 15 photodocumented at least 1 meal during the study period and 3 fully complied with the digital food record instructions. CONCLUSIONS: This study demonstrated digital food records as an acceptable tool in CBPR and identified contributors and barriers to the feasibility of digital food records for future research. Engaging community members in the implementation of novel assessment methods allows for the tailoring of technology to the needs of the community and optimizing community-based interventions. TRIAL REGISTRATION: ClinicalTrials.gov NCT01927783; https://www.clinicaltrials.gov/ct2/show/NCT01927783 (Archived by WebCite at http://www.webcitation.org/70WzaFWb6).
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BACKGROUND: Historically, Blacks have been disproportionately underrepresented in clinical trials. Outcomes associated with low Blacks' participation in research include poor understanding of the predictors and treatment of the disease, increasing health disparities, poor health equity, and suboptimal wellness of the nation as a whole. To address this gap in research participation, we analyzed our recruitment data to identify the most effective strategies for enrolling older Blacks in clinical trials. METHODS: Data used in these analyses were obtained from 3,266 potential volunteers, ages 50 or older, who completed a Mini-Mental State Exam as part of recruitment and screening for various clinical studies on Alzheimer's disease. In order to determine the most effective strategies for engaging Blacks in clinical research, we used tests of proportion to assess significant differences in recruitment sources, counts, and percentages for optimal recruitment strategies by gender. Finally, we employed regression analyses to confirm our findings. RESULTS: Of the total 3,266 screened, 2,830 Black volunteers were identified for further analysis. Overall, more women than men (73.8% vs 26.2%) participated in our recruitment activities. However, a significantly higher proportion of men than women were engaged through family (3.86% vs 1.30%, p=0.0004) and referral sources (5.89% vs 2.59%, p=0.0005). Compared to other sources for recruitment, we encountered a higher proportion of volunteers at health fairs (42.95%), and through advertisements (14.97%). In our sample, years of education and age did not appear to influence the likelihood of an encounter, screening, and potential participation. CONCLUSION: Our findings indicate Black men and women in our sample were predominantly recruited from health fairs and through advertisements tailored to their health needs and interests. Conversely, we mostly engaged Black men through family referrals and persons known to them, indicating a need for trust in their decision to engage study personnel and/or participate in clinical trials.
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Investigación Biomédica , Negro o Afroamericano , Selección de Paciente , Anciano , Femenino , Humanos , Masculino , Pruebas de Estado Mental y Demencia , Persona de Mediana Edad , Estados UnidosRESUMEN
OBJECTIVE: Melatonin has been widely studied in the treatment of sleep disorders and evidence is accumulating on a possible role for melatonin influencing mood. Our aim was to determine the efficacy and acceptability of melatonin for mood disorders. METHOD: We conducted a comprehensive systematic review of randomized clinical trials on patients with mood disorders, comparing melatonin to placebo. RESULTS: Eight clinical trials were included; one study in bipolar, three in unipolar depression and four in seasonal affective disorder. We have only a small study on patients with bipolar disorder, while we have more studies testing melatonin as an augmentation strategy for depressive episodes in major depressive disorder and seasonal affective disorder. The acceptability and tolerability were good. We analyzed data from three trials on depressive episodes and found that the evidence for an effect of melatonin in improving mood symptoms is not significant (SMD = 0.37; 95% CI [-0.05, 0.37]; P = 0.09). The small sample size and the differences in methodology of the trials suggest that our results are based on data deriving from investigations occurring early in this field of study. CONCLUSION: There is no evidence for an effect of melatonin on mood disorders, but the results are not conclusive and justify further research.
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Depresores del Sistema Nervioso Central/uso terapéutico , Melatonina/uso terapéutico , Trastornos del Humor/tratamiento farmacológico , Humanos , Resultado del TratamientoRESUMEN
STUDY DESIGN: Exploratory qualitative. OBJECTIVES: The aim of this study was to describe the experiences of bowel and bladder dysfunction on social activities and relationships in people with spinal cord injury living in the community. SETTING: People living with spinal cord injury experiencing bowel and bladder dysfunction. METHODS: Participants were recruited through the Australian Quadriplegic Association Victoria. Semi-structured in-depth interviews were undertaken with purposively selected participants to ensure representation of age, gender, spinal cord injury level and compensation status. A thematic analysis was performed to interpret patient experiences. RESULTS: Twenty-two participants took part in the study. Bladder and bowel dysfunction altered relationships because of issues with intimacy, strained partner relationships and role changes for family and friends. A lack of understanding from friends about bladder and bowel dysfunction caused frustration, as this impairment was often responsible for variable attendance at social activities. Issues with the number, location, access and cleanliness of bathrooms in public areas and in private residences negatively affected social engagement. Social activities were moderated by illness, such as urinary tract infections, rigid and unreliable bowel routines, stress and anxiety about incontinence and managing the public environment, and due to continuous changes in plans related to bowel and bladder issues. Social support and adaptation fostered participation in social activities. CONCLUSION: Tension exists between managing bowel and bladder dysfunction and the desire to participate in social activities. Multiple intersecting factors negatively affected the social relationships and activities of people with spinal cord injury and bowel and bladder dysfunction.
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Relaciones Interpersonales , Enfermedades del Recto/psicología , Conducta Social , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/psicología , Trastornos Urinarios/psicología , Adaptación Psicológica , Adolescente , Adulto , Familia/psicología , Femenino , Humanos , Vida Independiente , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Enfermedades del Recto/etiología , Enfermedades del Recto/rehabilitación , Parejas Sexuales/psicología , Apoyo Social , Traumatismos de la Médula Espinal/rehabilitación , Trastornos Urinarios/etiología , Trastornos Urinarios/rehabilitación , Adulto JovenRESUMEN
Wearable mobile health (mHealth) technologies offer approaches for targeting physical activity (PA) in resource-limited, community-based interventions. We sought to explore user characteristics of PA tracking, wearable technology among a community-based population within a health and needs assessment. In 2014-2015, we conducted the Washington, D.C., Cardiovascular Health and Needs Assessment in predominantly African-American churches among communities with higher obesity rates and lower household incomes. Participants received a mHealth PA monitor and wirelessly uploaded PA data weekly to church data collection hubs. Participants (n = 99) were 59 ± 12 years, 79% female, and 99% African-American, with a mean body mass index of 33 ± 7 kg/m2. Eighty-one percent of participants uploaded PA data to the hub and were termed "PA device users." Though PA device users were more likely to report lower household incomes, no differences existed between device users and non-users for device ownership or technology fluency. Findings suggest that mHealth systems with a wearable device and data collection hub may feasibly target PA in resource-limited communities.
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Acelerometría , Ejercicio Físico , Monitores de Ejercicio , Evaluación de Necesidades , Cooperación del Paciente , Tecnología Inalámbrica , Índice de Masa Corporal , Cristianismo , District of Columbia , Femenino , Conductas Relacionadas con la Salud , Humanos , Masculino , Persona de Mediana Edad , Obesidad , Pobreza , Telemedicina , Poblaciones VulnerablesRESUMEN
BACKGROUND: Resource-limited communities in Washington, D.C. have high rates of obesity-related cardiovascular disease in addition to inadequate physical activity (PA) facilities and limited Internet access. Engaging community members in the design and implementation of studies to address these health disparities is essential to the success of community-based PA interventions. OBJECTIVE: The objective of the study was to use qualitative and quantitative methods to evaluate the feasibility and acceptability of PA-monitoring wristbands and Web-based technology by predominantly African American, church-based populations in resource-limited Washington, D.C. neighborhoods. METHODS: To address cardiovascular health in at-risk populations in Washington, D.C., we joined community leaders to establish a community advisory board, the D.C. Cardiovascular Health and Obesity Collaborative (D.C. CHOC). As their first initiative, the Washington, D.C. Cardiovascular Health and Needs Assessment intends to evaluate cardiovascular health, social determinants of health, and PA-monitoring technologies. At the recommendation of D.C. CHOC members, we conducted a focus group and piloted the proposed PA-monitoring system with community members representing churches that would be targeted by the Cardiovascular Health and Needs Assessment. Participants (n=8) agreed to wear a PA-monitoring wristband for two weeks and to log cardiovascular health factors on a secure Internet account. Wristbands collected accelerometer-based data that participants uploaded to a wireless hub at their church. Participants agreed to return after two weeks to participate in a moderated focus group to share experiences using this technology. Feasibility was measured by Internet account usage, wristband utilization, and objective PA data. Acceptability was evaluated through thematic analysis of verbatim focus group transcripts. RESULTS: Study participants (5 males, 3 females) were African American and age 28-70 years. Participant wristbands recorded data on 10.1±1.6 days. Two participants logged cardiovascular health factors on the website. Focus group transcripts revealed that participants felt positively about incorporating the device into their church-based populations, given improvements were made to device training, hub accessibility, and device feedback. CONCLUSIONS: PA-monitoring wristbands for objectively measuring PA appear to be a feasible and acceptable technology in Washington, D.C., resource-limited communities. User preferences include immediate device feedback, hands-on device training, explicit instructions, improved central hub accessibility, and designation of a church member as a trained point-of-contact. When implementing technology-based interventions in resource-limited communities, engaging the targeted community may aid in early identification of issues, suggestions, and preferences. TRIAL REGISTRATION: ClinicalTrials.gov NCT01927783; https://clinicaltrials.gov/ct2/show/NCT01927783 (Archived by WebCite at http://www.webcitation.org/6f8wL117u).
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A two-year-old guinea pig presented for difficulty chewing. Examination and diagnostic imaging, including computed tomography and magnetic resonance, revealed an odontogenic retromasseteric abscess associated with a mandibular cheek tooth. Treatment included removal of the abscess and marsupialisation of the surgical site for repeated debridement and healing by second intention. Unique features of this case included the use of advanced diagnostic imaging and utilisation of marsupialisation for surgical correction.
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Absceso/veterinaria , Enfermedades Mandibulares/veterinaria , Absceso/diagnóstico por imagen , Absceso/cirugía , Animales , Cobayas , Masculino , Enfermedades Mandibulares/diagnóstico por imagen , Enfermedades Mandibulares/cirugía , Tomografía Computarizada por Rayos X/veterinariaRESUMEN
Preputial tumours in ferrets are frequently malignant and therefore warrant prompt investigation. As many cases do not respond favourably to surgery, even in combination with radiation therapy, wide surgical resection has been recommended. Such a procedure may necessitate partial or total penile resection but outcomes have thus far not been well described. The current case series describes two ferrets in which surgical resection, including penile amputation, was performed using 10 and 5 mm margins, respectively. In the first case, no recurrence of preputial gland adenocarcinoma was noted for 32 months postsurgery, whereas multiple attempts at surgery and radiation therapy were unsuccessful in the second. These cases suggest that margins of at least 1 cm may help achieve a better outcome. Penile amputation for the treatment of preputial tumours appears to be well tolerated by ferrets, as demonstrated by these cases.
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Hurones/cirugía , Neoplasias del Pene/veterinaria , Amputación Quirúrgica/métodos , Amputación Quirúrgica/veterinaria , Animales , Masculino , Neoplasias del Pene/cirugía , Pene/cirugíaRESUMEN
BACKGROUND: This paper places the importance of evidence-based models of interprofessional education (IPE) within the context of a changing National Health Service (NHS). The coalition government has placed integrated care at the heart of its vision for England's health system. Its principles are to put patients at the centre of the NHS, empower clinicians to lead commissioning and change the emphasis of measurement to quality clinical outcomes. As a result, NHS services are being increasingly tendered along evidence-based care pathways and commissioners are introducing payment by results tariffs, requiring providers to achieve quality outcomes as a requirement of full payment. AIM: We argue that in preparing the health and social care workforce for outcome-based practice, the development of technical skills should be complemented with skills for effective teamworking and collaborative practice. METHODS: This paper shares the achievements of the Leicester Model of IPE which is underpinned by theoretical models of learning and implemented entirely in clinical practice; mixed research methods demonstrate that its learning potential is as relevant today as when it was first implemented in 1996. RESULTS: Our extensive research evidence demonstrates that students and healthcare professionals undertaking these programmes are enabled to perceive care pathways from service and providers perspectives; they gain valuable insights into how teams balance task- and patient-related issues, offer clarity about the team's effectiveness and gain new insights into collaborative opportunities to address patients' needs. CONCLUSION: We demonstrate that models such as ours offer evidence-based solutions which will support the achievement of quality outcomes for service providers, many of whom are reviewing their business plans to address the financial implications of payment by results. The current NHS reforms provide a hugely important lever in which IPE can come of age - in return we need to ensure that our NHS colleagues are informed of its potential.
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Educación , Modelos Teóricos , Grupo de Atención al Paciente/normas , Atención al Paciente/normas , Mejoramiento de la Calidad , Humanos , Medicina EstatalRESUMEN
An adult pet rabbit (Oryctolagus cuniculus) presented with a progressively enlarging left testicle. Because neoplasia was suspected, the testicle was removed. Pathologic evaluation (exfoliative cytology, histopathology, immunohistochemistry, electron microscopy) indicated that the tumor was an intratesticular granular cell tumor. Granular cell tumor has not been described in rabbits before and has not been described in the testes of animals or postnatal humans. Granular cell tumor should be included as a differential diagnosis of testicular tumors, particularly Leydig cell tumor, because of potential histologic similarities.
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Tumor de Células Granulares/veterinaria , Conejos , Neoplasias Testiculares/veterinaria , Animales , Tumor de Células Granulares/diagnóstico , Tumor de Células Granulares/patología , Masculino , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/patología , Testículo/patologíaRESUMEN
At the Northern Illinois University Institute for Neutron Therapy at Fermilab, the clinical tissue-equivalent ionisation chamber response is measured every treatment day using a cesium source that was configured to match readings obtained at the National Bureau of Standards. Daily measurements are performed in air using the air-to-tissue dose conversion factors given in AAPM Report #7. The measured exposure calibration factors have been tabulated and graphed as a function of time from 1978 to present. For A-150 plastic ionisation chambers, these factors exhibit a sinusoidal variation with a period of approximately 1 y and amplitude of +/- 1%. This variation, attributable to the hygroscopic nature of A-150 plastic, is correlated with the relative humidity of the facility, and is greater than the humidity corrections for gas described in the literature. The data suggest that chamber calibration should be performed at least weekly to accommodate these variations.
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Terapia por Captura de Neutrón de Boro/instrumentación , Neutrones , Plásticos/efectos de la radiación , Monitoreo de Radiación/instrumentación , Protección Radiológica/instrumentación , Illinois , Iones , Dosis de Radiación , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
In boron neutron capture therapy and boron neutron capture enhanced fast neutron therapy, the absorbed dose of tissue due to the boron neutron capture reaction is difficult to measure directly. This dose can be computed from the measured thermal neutron fluence rate and the (10)B concentration at the site of interest. A borated tissue-equivalent (TE) ion chamber can be used to directly measure the boron dose in a phantom under irradiation by a neutron beam. Fermilab has two Exradin 0.5 cm(3) Spokas thimble TE ion chambers, one loaded with boron, available for such measurements. At the Fermilab Neutron Therapy Facility, these ion chambers are generally used with air as the filling gas. Since alpha particles and lithium ions from the (10)B(n,alpha)(7)Li reactions have very short ranges in air, the Bragg-Gray principle may not be satisfied for the borated TE ion chamber. A calibration method is described in this paper for the determination of boron capture dose using paired ion chambers. The two TE ion chambers were calibrated in the thermal column of the National Institute of Standards and Technology (NIST) research reactor. The borated TE ion chamber is loaded with 1,000 ppm of natural boron (184 ppm of (10)B). The NIST thermal column has a cadmium ratio of greater than 400 as determined by gold activation. The thermal neutron fluence rate during the calibration was determined using a NIST fission chamber to an accuracy of 5.1%. The chambers were calibrated at two different thermal neutron fluence rates: 5.11 x 10(6) and 4.46 x 10(7)n cm(-2) s(-1). The non-borated ion chamber reading was used to subtract collected charge not due to boron neutron capture reactions. An optically thick lithium slab was used to attenuate the thermal neutrons from the neutron beam port so the responses of the chambers could be corrected for fast neutrons and gamma rays in the beam. The calibration factor of the borated ion chamber was determined to be 1.83 x 10(9) +/- 5.5% (+/- 1sigma) n cm(-2) per nC at standard temperature and pressure condition.
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Terapia por Captura de Neutrón de Boro/instrumentación , Terapia por Captura de Neutrón de Boro/normas , Neutrones , Monitoreo de Radiación/instrumentación , Monitoreo de Radiación/normas , Protección Radiológica/instrumentación , Protección Radiológica/normas , Ácidos Bóricos/química , Ácidos Bóricos/efectos de la radiación , Calibración , Iones , Dosis de Radiación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estados UnidosRESUMEN
OBJECTIVE: It is known that stunting and obesity affect a large proportion of children in the world, and these can be affected by the physical activity levels of the children. In the present study, we evaluated the association between physical activity, physical development and body composition in black adolescent children. DESIGN: Cross-sectional study. SETTING: Black township schools in the North West Province, South Africa. METHODS: Three-hundred and thirteen grade 8 children were included in the Physical Activity in Youth study. Anthropometric measurements, body composition measures and maturity level as assessed by Tanner stages were determined in these children. In addition, Previous Day Physical Activity Recall questionnaires were administered on the children to record the various activities they undertake daily. RESULTS: The demographic characteristics of the children showed a high level of homogeneity. A high prevalence of stunting (16.3%) was observed in the children, which was higher in boys than in girls (21.6 vs. 12.3%). Also prevalent was overweight/obesity (8.6%), but this was higher in girls than in boys (13.4 vs. 1.6%). The children also showed a reduction in levels of physical activity with advancement in maturity; furthermore, boys showed a more central form of fat deposition whilst girls showed more gynoid deposition. CONCLUSIONS: The study revealed that physical activity plays a role in determining body composition, and further indicated that physical activity is associated with favourable body composition measures. Children who were more active were likely to have less fat deposits.
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Composición Corporal , Ejercicio Físico , Adolescente , Población Negra , Niño , Estudios Transversales , Femenino , Vivienda , Humanos , Actividades Recreativas , Masculino , Sobrepeso , Prevalencia , Sudáfrica/epidemiología , Encuestas y CuestionariosRESUMEN
We describe a new technique for achieving a deep cervical plexus block using a portable vascular access ultrasound scanner (Site-Rite II, Bard Access Systems, Pittsburgh, PA).
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Plexo Cervical/efectos de los fármacos , Plexo Cervical/diagnóstico por imagen , Bloqueo Nervioso/métodos , Ultrasonografía Intervencional/métodos , Plexo Cervical/anatomía & histología , Humanos , Ultrasonografía Doppler/métodos , Arteria Vertebral/diagnóstico por imagenRESUMEN
A new 4 week community programme, developed through a successful Department of Health Bid in partnership with the Community NHS Trust, provides a vital clinical learning block for all medical students at the Leicester/Warwick Medical school. The course owes its success to the pivotal role played by nurses. Working with an Academic co-ordinator the course was operationalised in the county's market towns and provided student access to the work of the entire front line community workforce in the care of people with life limiting diseases and disabled people. Senior nurses in each locality led the work with both community hospital and community nurses sharing their expertise with a wide range of front line health and social care professionals. The lead nurses and their teaching teams attended university training days prior to developing a locality student programme and played a key role in identifying preparing and supporting suitable patients for student learning. Students highly praised the work of the lead nurses who supported their learning throughout the course. All nurses felt the educational involvement was worthwhile, having overcome identified barriers and with funding support nurses have been able to assimilate the teaching into their annual workload.
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PURPOSE: To assess patient comfort with and without intravenous (i.v.) cannulation during 1-quadrant sub-Tenon's anesthesia during phacoemulsification. SETTING: Royal Alexandra Hospital, Paisley, Scotland, United Kingdom. METHODS: This prospective masked controlled clinical trial comprised 119 patients having elective clear corneal phacoemulsification. Fifty had sub-Tenon's anesthesia with an i.v. cannula; 23, sub-Tenon's anesthesia without an i.v. cannula; and 46, topical anesthesia of proparacaine 0.5% without an i.v. cannula. No patient received sedation. All patients had clear corneal phacoemulsification with foldable posterior chamber intraocular lens implantation. The patients' subjective pain experience was measured immediately after surgery by a single independent observer using a 10-point visual analog scale. RESULTS: The mean patient-reported pain was low in all 3 groups. The mean i.v. cannula-related pain score in the sub-Tenon's group with an i.v. cannula (1.00; range 0 to 8) was higher than the mean general pain score (0.46; range 0 to 5) and worst pain experienced during surgery score (0.64; range 0 to 3). In the topical anesthesia group, 8 patients (17%) reported greater discomfort directly or indirectly related to the subconjunctival antibiotic injection at the end of surgery. CONCLUSION: Patient-reported pain caused by placing an i.v. cannula in the sub-Tenon's group significantly altered overall patient comfort during the surgical experience. Thus, the routine use of i.v. access during clear corneal phacoemulsification under sub-Tenon's anesthesia should be avoided to improve patient satisfaction.
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Anestesia Local/métodos , Córnea/cirugía , Satisfacción del Paciente , Facoemulsificación/métodos , Adulto , Anciano , Anciano de 80 o más Años , Anestésicos Locales/administración & dosificación , Cateterismo/métodos , Tejido Conectivo , Método Doble Ciego , Femenino , Humanos , Implantación de Lentes Intraoculares , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Dolor Postoperatorio/fisiopatología , Estudios ProspectivosRESUMEN
We describe the clinical features and management of a 36-year-old man with aniridia and aphakia following blunt ocular trauma. Examination showed partial aniridia and aphakia. We discuss the various options available in the management of this patient and describe the surgical technique involved in the implantation of an iris reconstruction implant.
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Aniridia/cirugía , Afaquia Poscatarata/cirugía , Iris/lesiones , Procedimientos Quirúrgicos Oftalmológicos , Procedimientos de Cirugía Plástica , Implantación de Prótesis , Adulto , Aniridia/etiología , Afaquia Poscatarata/etiología , Lesiones Oculares/etiología , Lesiones Oculares/cirugía , Humanos , Iris/cirugía , Cristalino/lesiones , Cristalino/cirugía , Masculino , Heridas por Arma de Fuego/complicaciones , Heridas no Penetrantes/etiología , Heridas no Penetrantes/cirugíaRESUMEN
The ICRU tissue to A-150 tissue equivalent plastic kerma ratio is needed for neutron therapy dosimetry. The current ICRU protocol for neutron dosimetry recommends using a common conversion factor of 0.95 at all high-energy neutron therapy facilities. In an effort to determine facility specific ICRU tissue to A-150 plastic kerma ratios, an experimental approach was pursued. Four low pressure proportional counters that differed in wall materials (i.e. A-150, carbon, zirconium and zirconium-oxide) were used as dosimeters and integral kerma ratios were determined directly in the clinical beam. Measurements were performed at two p(66)Be facilities: iThemba LABS near Cape Town and Fermilab near Chicago. At the iThemba facility the clinical neutron beam is routinely filtered by a flattening and hardening filter combination. The influence of beam filtration on the kerma ratio was evaluated. Using two recent gas-to-wall dose conversion factor (r(m,g) value) evaluations a mean ICRU tissue to A-150 plastic kerma ratio of 0.93 +/- 0.05 was determined for the clinical beam at iThemba LABS. The respective value for the Fermilab beam is 0.95 +/- 0.05. The experimentally determined ICRU tissue to A-150 plastic kerma ratios for the two clinical beams are in agreement with theoretical evaluations. Beam filtration reduces the kerma ratio by 3 +/- 2%.
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Neutrones Rápidos/uso terapéutico , Planificación de la Radioterapia Asistida por Computador/estadística & datos numéricos , Fenómenos Biofísicos , Biofisica , Humanos , Neoplasias/radioterapia , Fantasmas de Imagen , Plásticos , Radiometría/instrumentaciónRESUMEN
Existing health promotion messages and advice on smoking cessation focus upon the negative aspects of continuing to smoke and contrast these to the benefits of giving up. Benefits of cessation are invariably linked to reduced risks of illness and disease with the process of cessation framed as a largely positive and certainly a health enhancing one. In this paper we present an analysis of data from a cross-sectional, exploratory study in the city of Aberdeen, Scotland, undertaken with 54 people, aged 18-44, who are or have been smokers. The multiple and often contradictory agendas of everyday life, smoking and health are explored. Participants spoke of the dangers of smoking and the potential benefits of giving up as these are considered by health promotion and medical research. However, many smokers experienced a number of benefits from smoking (such as socialising with others and breaks from boredom), and health and social problems with the process of cessation (for example, weight gain, stress, colds, flu). Participants appeared to query the validity of the risks of continuing to smoke and yet indicate a range of health and social difficulties in giving up. The authors assert that an acknowledgement of the attractive, pleasurable aspects of smoking may be seen as unacceptable and irresponsible but this could well provide an opportunity to relate to the everyday and multiple practices of smoking and smokers themselves as illuminated by this research.