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1.
High Educ (Dordr) ; 84(6): 1267-1281, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36284646

RESUMEN

Student learning experiences at university are constantly evolving; new disciplinary discoveries, new knowledge, interdisciplinary synergies and new exigencies make learning a dynamic experience for students, teachers and researchers alike; and that is just the what of learning. Add to this, changes in the how of learning, new pedagogies and new technologies, new partners in the provision of learning, as well as new configurations of where learning takes place, such as on campus, at home, in the workplace and online; and it is not hard to make the case that learning experiences of students enrolled in a degree are relatively more complex today than they were even 20 years ago. Much of this change has been captured over the last five decades in the journal Higher Education. The ongoing challenge of these changes is the complexity that accompanies them. How do we improve the student experience of learning in a complex context? What should the outcomes of a higher education degree be? What learning processes are likely to lead better outcomes? How do you assess the quality of learning that may occur in small groups on campus or online, or in large groups in both places, or in laboratories or the workplace? What is the role of material objects in these experiences and do they contribute to outcomes? This manuscript will consider such questions and where the journal is pointing researchers towards new avenues that are developing in learning and teaching internationally.

2.
Br J Dermatol ; 186(4): 694-704, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34773645

RESUMEN

BACKGROUND: For patients with early American Joint Committee on Cancer (AJCC)-stage melanoma the combined loss of the autophagy regulatory protein AMBRA1 and the terminal differentiation marker loricrin in the peritumoral epidermis is associated with a significantly increased risk of metastasis. OBJECTIVES: The aim of the present study was to evaluate the potential contribution of melanoma paracrine transforming growth factor (TGF)-ß signalling to the loss of AMBRA1 in the epidermis overlying the primary tumour and disruption of epidermal integrity. METHODS: Immunohistochemistry was used to analyse AMBRA1 and TGF-ß2 in a cohort of 109 AJCC all-stage melanomas, and TGF-ß2 and claudin-1 in a cohort of 30 or 42 AJCC stage I melanomas, respectively, with known AMBRA1 and loricrin (AMLo) expression. Evidence of pre-ulceration was analysed in a cohort of 42 melanomas, with TGF-ß2 signalling evaluated in primary keratinocytes. RESULTS: Increased tumoral TGF-ß2 was significantly associated with loss of peritumoral AMBRA1 (P < 0·05), ulceration (P < 0·001), AMLo high-risk status (P < 0·05) and metastasis (P < 0·01). TGF-ß2 treatment of keratinocytes resulted in downregulation of AMBRA1, loricrin and claudin-1, while knockdown of AMBRA1 was associated with decreased expression of claudin-1 and increased proliferation of keratinocytes (P < 0·05). Importantly, we show loss of AMBRA1 in the peritumoral epidermis was associated with decreased claudin-1 expression (P < 0·05), parakeratosis (P < 0·01) and cleft formation in the dermoepidermal junction (P < 0·05). CONCLUSIONS: Collectively, these data suggest a paracrine mechanism whereby TGF-ß2 causes loss of AMBRA1 overlying high-risk AJCC early-stage melanomas and reduced epidermal integrity, thereby facilitating erosion of the epidermis and tumour ulceration.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Factor de Crecimiento Transformador beta2/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Epidermis/metabolismo , Humanos , Melanoma/patología , Neoplasias Cutáneas/patología , Factor de Crecimiento Transformador beta/metabolismo , Factores de Crecimiento Transformadores/metabolismo
3.
Rev Sci Instrum ; 91(2): 026104, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32113407

RESUMEN

We have demonstrated a vacuum suitcase to transport samples in vacuo to a surface analysis station for characterization of tokamak plasma facing components (PFCs). This technique enables surface analysis at powerful, dedicated stations that are not encumbered by design constraints imposed on them by a tokamak. The vacuum suitcase is an alternative solution to characterizing PFCs using diagnostics that are designed and built around a tokamak. The vacuum suitcase, called the Sample Exposure Probe (SEP), features mobile ultra-high vacuum pumping. Active pumping under high vacuum enables sample transfer between the Lithium Tokamak eXperiment-ß (LTX-ß) and a high resolution X-ray Photoelectron Spectroscopy (XPS) system that is situated close by. A thermocouple inserted in the back of the sample head measures heat flux from the plasma during exposure, and together with a button heater, allows the sample to match the LTX-ß PFCs in high temperature operations. As vacuum conditions are better during transfer and analysis than in the tokamak, less contamination is introduced to the samples. XPS scans on a dedicated analysis station enable peak identification due to higher resolution and signal to noise ratio. A similar probe could be implemented for other fusion devices. The SEP is the first vacuum suitcase implementation for fusion applications that incorporates active pumping.

4.
Faraday Discuss ; 200: 379-395, 2017 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-28640319

RESUMEN

In many parts of the world, the implementation of air quality regulations has led to significant decreases in SO2 emissions with minimal impact on NH3 emissions. In Canada and the United States, the molar ratio of NH3 : SO2 emissions has increased dramatically between 1990 and 2014. In many regions of North America, this will lead the molar ratio of NHx : SO4, where NHx is the sum of particle phase NH4+ and gas phase NH3, and SO4 is the sum of particle phase HSO4- and SO42-, to exceed 2. A thermodynamic model (E-AIM model II) is used to investigate the sensitivity of particle pH, and the gas-particle partitioning of NHx and inorganic nitrate, to the atmospheric NHx : SO4 ratio. Steep increases in pH and the gas fraction of NHx are found as NHx : SO4 varies from below 1 to above 2. The sensitivity of the gas fraction of nitrate also depends strongly on temperature. The results show that if NHx : SO4 exceeds 2, and the gas and particle phase NHx are in equilibrium, the particle pH will be above 2. Observations of the composition of particulate matter and gas phase NH3 from two field campaigns in southern Canada in 2007 and 2012 have median NHx : SO4 ratios of 3.8 and 25, respectively. These campaigns exhibited similar amounts of NH3, but very different particle phase loadings. Under these conditions, the pH values calculated using the observations as input to the E-AIM model were in the range of 1-4. The pH values were typically higher at night because the higher relative humidity increased the particle water content, diluting the acidity. The assumption of equilibration between the gas and particle phase NHx was evaluated by comparing the observed and modelled gas fraction of NHx. In general, E-AIM was able to reproduce the partitioning well, suggesting that the dominant constituents contributing to particle acidity were measured, and that the estimated pH values were realistic. These results suggest that regions of the world where the ratio of NH3 : SO2 emissions is beginning to exceed 2 on a molar basis may be experiencing rapid increases in aerosol pH of 1-3 pH units. This could have important consequences for the rates of condensed phase reactions that are acid-catalyzed.

6.
Rev Sci Instrum ; 83(10): 10D703, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23126877

RESUMEN

The objective of the materials analysis particle probe (MAPP) in NSTX is to enable prompt and direct analysis of plasma-facing components exposed to plasma discharges. MAPP allows multiple samples to be introduced to the level of the plasma-facing surface without breaking vacuum and analyzed using X-ray photoelectron spectroscopy (XPS), ion-scattering and direct recoil spectroscopy, and thermal desorption spectroscopy (TDS) immediately following the plasma discharge. MAPP is designed to operate as a diagnostic within the ∼12 min NSTX minimum between-shot time window to reveal fundamental plasma-surface interactions. Initial calibration demonstrates MAPP's XPS and TDS capabilities.

8.
Int Endod J ; 38(6): 364-71, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15910471

RESUMEN

AIM: To investigate the effects of cryogenic treatment on nickel-titanium endodontic instruments. The null hypothesis was that cryogenic treatment would result in no changes in composition, microhardness or cutting efficiency of nickel-titanium instruments. METHODOLOGY: Microhardness was measured on 30 nickel-titanium K-files (ISO size 25) using a Vicker's indenter. Elemental composition was measured on two instruments using X-ray spectroscopy. A nickel-titanium bulk specimen was analysed for crystalline phase composition using X-ray diffraction. Half of the specimens to be used for each analysis were subjected to a cryogenic treatment in liquid nitrogen (-196 degrees C) for either 3 s (microhardness specimens) or 10 min (other specimens). Cutting efficiency was assessed by recording operator choice using 80 nickel-titanium rotary instruments (ProFile 20, .06) half of which had been cryogenically treated and had been distributed amongst 14 clinicians. After conditioning by preparing four corresponding canals, each pair of instruments were evaluated for cutting efficiency by a clinician during preparation of one canal system in vitro. A Student's t-test was used to analyse the microhardness data, and a binomial test was used to analyse the observer choice data. Composition data were analysed qualitatively. RESULTS: Cryogenically treated specimens had a significantly higher microhardness than the controls (P < 0.001; beta > 0.999). Observers showed a preference for cryogenically treated instruments (61%), but this was not significant (P = 0.21). Both treated and control specimens were composed of 56% Ni, 44% Ti, 0% N (by weight) with a majority in the austenite phase. CONCLUSIONS: Cryogenic treatment resulted in increased microhardness, but this increase was not detected clinically. There was no measurable change in elemental or crystalline phase composition.


Asunto(s)
Aleaciones Dentales , Instrumentos Dentales , Tratamiento del Conducto Radicular/instrumentación , Frío , Aleaciones Dentales/química , Análisis del Estrés Dental , Dureza , Ensayo de Materiales , Níquel/química , Nitrógeno , Espectrometría por Rayos X , Titanio/química , Difracción de Rayos X
10.
Qual Manag Health Care ; 7(2): 50-9, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10346462

RESUMEN

In today's health care marketplace, quality has become an expectation. Stakeholders are demanding quality clinical outcomes, and accrediting bodies are requiring clinical performance data. The Roosevelt Institute's quest was to define and quantify quality outcomes, develop an organizational culture of performance improvement, and ensure customer satisfaction. Several of the organization's leaders volunteered to work as a team to develop a specific performance improvement approach tailored to the organization. To date, over 200 employees have received an orientation to the model and its philosophy and nine problem action and process improvement teams have been formed.


Asunto(s)
Centros de Rehabilitación/normas , Gestión de la Calidad Total/organización & administración , Georgia , Humanos , Joint Commission on Accreditation of Healthcare Organizations , Participación en las Decisiones , Cultura Organizacional , Evaluación de Resultado en la Atención de Salud , Satisfacción del Paciente , Técnicas de Planificación , Centros de Rehabilitación/organización & administración , Gestión de la Calidad Total/métodos
11.
Plast Reconstr Surg ; 101(5): 1205-11, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9529202

RESUMEN

The sphincter pharyngoplasty is a surgical procedure designed to correct velopharyngeal dysfunction. Its advocates cite the theoretical advantage of its induction of dynamic activity of the neovelopharyngeal port, but this dynamic activity has yet to be quantitatively demonstrated in the literature. The purpose of this study was to quantify postoperative velopharyngeal dynamism and to document the results of intervention outcome on sphincteric excursion measurements from minimal-to-maximal orifice closure. We conducted a 7-year retrospective review of speech videofluoroscopy evaluations in patients who had undergone sphincter pharyngoplasty in our center. Between 1989 and 1994, there were 58 patients so treated for postpalatoplasty velopharyngeal dysfunction by two surgeons using the same operative technique. Patients for whom sphincter pharyngoplasty was recommended fulfilled both of the following criteria: (1) velopharyngeal dysfunction caused by an anatomic, myoneural, or combined deficiency of the velopharyngeal sphincter that would not be expected to be managed by speech therapy alone, and (2) preoperative videonasendoscopy and speech videofluoroscopic studies that demonstrated large-gap coronal, circular, or bow-tie closure patterns or velopharyngeal hypodynamism. Of the original 58 patients, 24 underwent postoperative speech videofluoroscopic evaluations with basal views. Of these, 20 of the evaluations (83 percent) were of adequate quality to be included in a research study. Still images showing maximum and minimum excursion of the sphincter in basal view were obtained. To test for observer reliability, the speech videofluoroscopic studies were randomized and presented for measurement to the same individual on two occasions, each session separated by a 1-month time interval. Topographic imaging software was used to obtain maximum and minimum measurements to within 0.1 mm. Partitioning the variance of the data showed that measurement variability was a very small portion of the total, and that difference between the minimum and maximum values was the largest source of variability. Of the total variability in the data, 64.0 percent originated in the minimum/maximum difference, 34.3 percent came from patient variability, and only 1.7 percent resulted from original or repeat measurements. The patient variability may be exaggerated because of variability in the scale of measurement. Results of this study indicate a quantifiable and statistically significant difference in maximum-to-minimum excursion of sphincteric closure. Sphincter pharyngoplasty appears to be dynamic in the majority of cases.


Asunto(s)
Paladar Blando/fisiología , Faringe/fisiología , Insuficiencia Velofaríngea/cirugía , Adolescente , Análisis de Varianza , Niño , Preescolar , Cinerradiografía , Endoscopía , Estudios de Evaluación como Asunto , Femenino , Fluoroscopía , Humanos , Masculino , Contracción Muscular/fisiología , Variaciones Dependientes del Observador , Músculos Palatinos/fisiopatología , Paladar Blando/diagnóstico por imagen , Músculos Faríngeos/fisiopatología , Faringe/diagnóstico por imagen , Faringe/cirugía , Reproducibilidad de los Resultados , Estudios Retrospectivos , Método Simple Ciego , Habla/fisiología , Resultado del Tratamiento , Insuficiencia Velofaríngea/diagnóstico por imagen , Insuficiencia Velofaríngea/fisiopatología , Grabación de Cinta de Video
12.
South Med J ; 83(6): 690-4, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2162571

RESUMEN

We have reported the case of a 69-year-old woman with a hugh benign fibrous tumor of the left pleura and hypoglycemic seizures. Increased preoperative levels of insulin-like growth factor (IGF II) were present; insulin level was low and plasma levels of somatomedin C were normal. After resection of the 2,400 gm tumor, blood sugar level has remained normal, and IGF II has fallen to normal limits. This appears to be the first reported case documenting elevated serum IGF II in association with a benign fibrous pleural tumor.


Asunto(s)
Carcinoma de Células Pequeñas/patología , Hipoglucemia/etiología , Factor II del Crecimiento Similar a la Insulina/análisis , Neoplasias Pleurales/patología , Somatomedinas/análisis , Anciano , Carcinoma de Células Pequeñas/sangre , Carcinoma de Células Pequeñas/complicaciones , Carcinoma de Células Pequeñas/diagnóstico por imagen , Carcinoma de Células Pequeñas/cirugía , Femenino , Humanos , Hipoglucemia/sangre , Neoplasias Pleurales/sangre , Neoplasias Pleurales/complicaciones , Neoplasias Pleurales/diagnóstico por imagen , Neoplasias Pleurales/cirugía , Pronóstico , Síndrome , Tomografía Computarizada por Rayos X
13.
J Am Mosq Control Assoc ; 6(1): 55-63, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1969927

RESUMEN

Development times and survival of immatures and reproductive diapause of adult females of Culex tarsalis, Cx. restuans and Culiseta inornata were investigated from hatching to adult emergence at 15, 20 and 25 degrees C in the laboratory and at natural temperatures and photoperiods in southern Manitoba. Based on patterns of oviposition in artificial pools operated from mid-April to the end of September and development time of the immature stages, 3 generations of Cx. tarsalis, Cx. restuans and Cs. inornata were possible in 1980 and 1981. In 1981, 70% of field-reared Cx. tarsalis females emerging in mid-August were in diapause. Field-reared Cx. restuans and Cs. inornata entered reproductive diapause 2-3 weeks later than Cx. tarsalis.


Asunto(s)
Culex/fisiología , Culicidae/fisiología , Oviposición/fisiología , Animales , Culex/crecimiento & desarrollo , Culicidae/crecimiento & desarrollo , Femenino , Manitoba , Óvulo , Valores de Referencia , Reproducción/fisiología , Estaciones del Año , Especificidad de la Especie
14.
J Adv Nurs ; 14(7): 546-52, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2768682

RESUMEN

This paper presents part of the findings of an extensive empirical evaluation of a communication skills training programme for health visitor students. The programme was designed to develop the health visitors' ability to communicate with clients. A wide range of interpersonal skills were addressed and the training format involved skill analysis, roleplay practice and video-recorded feedback. The method of evaluation included an appraisal of the health visitors' social behaviour in a roleplay of a home-visit to a pregnant client. Data were collected, both before and following training, in an attempt to assess changes in trainee behaviour. The analysis took the form of a detailed frequency measurement of behavioural elements of health visitor performance, and a global rating of social competence by independent judges. Results of the analyses indicated that 14 out of the 20 behavioural variables changed in the desired direction. Thus, for example, following training the health visitors used significantly more open questions and verbal encouragers, and significantly fewer multiple questions and interruptions when communicating with the client. They were also rated significantly higher on the rating scale for social competence following training. These findings would seem to suggest that the training programme had a considerable degree of success. The findings are discussed in terms of the implications for development of health visitors' social skills, the need for more sophisticated measures of social behaviour and for the formulation of a model of competent professional practice in this area.


Asunto(s)
Comunicación , Enfermería en Salud Comunitaria/educación , Relaciones Interpersonales , Evaluación Educacional , Humanos , Evaluación de Programas y Proyectos de Salud , Desempeño de Papel , Conducta Social , Grabación de Cinta de Video
15.
Am J Physiol ; 246(6 Pt 2): F835-44, 1984 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6742132

RESUMEN

Studies were carried out in anesthetized rats comparing dynamics and pathways of interstitial fluid (ISF) drainage from different regions of brain. Rates of drainage from brain and flow into cerebrospinal fluid (CSF) were estimated from the efflux from brain and influx into CSF of radioiodinated albumin (RISA) following microinjection into caudate nucleus, internal capsule, or midbrain: pathways of flow through the subarachnoid space and into lymph were traced from the distribution of horseradish peroxidase and/or Evans blue-labeled albumin after injection into brain. ISF drainage rates (mul X g brain-1 X min-1) estimated for the three injection sites were 0.18, 0.19, and 0.29, respectively. Flow of ISF into bulk CSF sampled from the cisterna magna accounted for 60-75% of efflux from midbrain but only 10-15% of efflux from caudate nucleus or internal capsule. RISA was concentrated in the subarachnoid space, relative to bulk CSF, in sleeves of adventitial tissue surrounding pericerebral arteries, possibly accounting for the low recovery of isotope from bulk CSF. From the subarachnoid space, some fluid drained via olfactory nerve sheaths to retropharyngeal lymph nodes.


Asunto(s)
Líquidos Corporales/metabolismo , Encéfalo/fisiología , Animales , Peroxidasa de Rábano Silvestre , Radioisótopos de Yodo , Cinética , Matemática , Modelos Biológicos , Especificidad de Órganos , Ratas , Albúmina Sérica
16.
Nurse Pract ; 9(5): 26-34, 66, 1984 May.
Artículo en Inglés | MEDLINE | ID: mdl-6728347

RESUMEN

Nails can act as a barometer of an individual's health, offer clues to nutritional disturbances and serve as windows through which to view capillary changes associated with constitutional disease. Understanding growth and development of normal nails is essential to the identification and interpretation of nail pathology. Causes of onychopathology include genetic disease, trauma, tumors, dermatologic disease, miscellaneous acquired disorders and generalized systemic disease. Diagnosis is aided by the realization that the nails have a limited number of reaction patterns when disturbed by disease. Any of these reactions may manifest a host of disorders. Clinicians should remember to include the nails in patient assessment. The nails are interesting anatomical and physiological areas that can help make a diagnosis.


Asunto(s)
Enfermedades de la Uña/diagnóstico , Envejecimiento , Humanos , Enfermedades de la Uña/genética , Uñas/anatomía & histología , Uñas/fisiología , Uñas/fisiopatología , Neoplasias/diagnóstico
17.
Surv Synth Pathol Res ; 3(4): 333-41, 1984.
Artículo en Inglés | MEDLINE | ID: mdl-6390623

RESUMEN

PDMs tend to be large and the size is generally in proportion to fetal size. Infarcts are both more numerous and more common in PDMs than in normal placentas. These reflect the in utero hypoxia found in IDMs. Placental infarcts are increased not only in cases of severe DM (classes D, F-R) but also mild and early DM (class A). We infer from this that maternal vascular disease may be present functionally long before pathologic changes can be detected by direct examination of vessels. More subtle evidence of hypoxia in PDMs, such as an increased number of syncytial knots, has been suggested by qualitative data but has not been confirmed by morphometric analysis. Other qualitative observations in PDMs include thickened basement membranes, flattened microvilli on trophoblasts, ectasia of capillaries and villous stromal edema; changes in intracellular organelles and structures include enlarged mitochondria, increased pinocytotic vesicles, and dilated profiles of endoplasmic reticulum. Quantitative morphometric analysis shows no differences between normal placentas and PDMs with regard to these changes. The transport and secretory functions of the placenta, especially important in pregnancy complicated by DM, are not addressed here. As our understanding of placental physiology enlarges, it will be useful to relate each function with its structural counterpart. Perhaps this review will in part provide rational data from which to proceed with the task.


Asunto(s)
Enfermedades Placentarias/fisiopatología , Embarazo en Diabéticas/fisiopatología , Femenino , Humanos , Tamaño de los Órganos , Placenta/anatomía & histología , Placenta/fisiología , Embarazo
18.
Am J Cardiol ; 52(9): 62D-65D, 1983 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-6356866

RESUMEN

Data from 6 controlled clinical trials of oxprenolol carried out in the United States were reviewed to determine the efficacy and tolerability of oxprenolol in patients aged greater than or equal to 55 years. All study designs but 1 called for dosage to be increased to a maximum of 480 mg/day. In a 10-week trial of oxprenolol versus placebo given twice daily, oxprenolol reduced diastolic pressure by 8 mm Hg, while placebo reduced it by 3 mm Hg. A comparison of once-daily with twice-daily dosing showed similar results for both groups: -12/-6 mm Hg for once-daily and -9/-8 mm Hg for twice-daily. There were 2 short-term studies comparing oxprenolol and placebo, both given in addition to hydrochlorothiazide. In the first, the change in blood pressure with oxprenolol was -18/-14 mm Hg and with placebo was +6/-3 mm Hg; only 3 of 14 patients receiving oxprenolol received a maximal dosage. In the follow-up study, most of the dosages were titrated to maximum; reductions were -9/-9 mm Hg with oxprenolol treatment and 0/-12 mm Hg with placebo. Two long-term studies compared oxprenolol and propranolol, also as combination therapy with hydrochlorothiazide. In the 14-week study, the reduction in blood pressure was slightly better with oxprenolol: -15/-15 versus -12/-11 mm Hg. In the 27-week study, almost half of the patients in the oxprenolol group received the maximal dosage. Blood pressure was reduced 2 or 3 mm Hg less with oxprenolol than with propranolol. Oxprenolol was well tolerated in the elderly; it produced a low incidence of typical beta-blocker side effects even when given in a once-daily regimen.


Asunto(s)
Envejecimiento/efectos de los fármacos , Oxprenolol/uso terapéutico , Anciano , Ensayos Clínicos como Asunto , Quimioterapia Combinada , Tolerancia a Medicamentos , Humanos , Hidroclorotiazida/administración & dosificación , Hipertensión/tratamiento farmacológico , Persona de Mediana Edad , Oxprenolol/administración & dosificación , Oxprenolol/efectos adversos , Placebos
19.
Occup Health Nurs ; 29(7): 34-8, 1981 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6911489
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