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1.
Ultramicroscopy ; 260: 113951, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38471412

RESUMO

A scanning helium microscope typically utilises a thermal energy helium atom beam, with an energy and wavelength (¡100meV, ∼0.05 nm) particularly sensitive to surface structure. An angular detector stage for a scanning helium microscope is presented that facilitates the in-situ measurement of scattering distributions from a sample. We begin by demonstrating typical elastic and inelastic scattering from ordered surfaces. We then go on to show the role of topography in diffuse scattering from disordered surfaces, observing deviations from simple cosine scattering. In total, these studies demonstrate the wealth of information that is encoded into the scattering distributions obtained with the technique.

2.
Phys Chem Chem Phys ; 24(43): 26539-26546, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36305197

RESUMO

In understanding the nature of contrast in the emerging field of neutral helium microscopy, it is important to identify if there is an atom-surface scattering distribution that can be expected to apply broadly across a range of sample surfaces. Here we present results acquired in a scanning helium microscope (SHeM) under typical operating conditions, from a range of surfaces in their native state, i.e. without any specialist sample preparation. We observe diffuse scattering, with an approximately cosine distribution centred about the surface normal. The 'cosine-like' distribution is markedly different from those distributions observed from the well-prepared, atomically pristine, surfaces typically studied in helium atom scattering experiments. Knowledge of the typical scattering distribution in SHeM experiments provides a starting basis for interpretation of topographic contrast in images, as well as a reference against which more exotic contrast mechanisms can be compared.

3.
Ultramicroscopy ; 233: 113453, 2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35030513

RESUMO

Resolution is a key parameter for microscopy, but methods for standardizing its definition are often poorly defined. For a developing technique such as scanning helium microscopy, it is critical that a consensus-based protocol for determining instrument resolution is prepared as a written standard to allow both comparable quantitative measurements of surface topography and direct comparisons between different instruments. In this paper we assess a range of quantitative methods for determining instrument resolution and determine their relative merits when applied to the specific case of the scanning helium microscope (SHeM). Consequently, we present a preliminary protocol for measuring the resolution in scanning helium microscopy based upon utilizing appropriate test samples with sets of slits of well-defined dimensions to establish the quantitative resolution of any similar instrument.

4.
Pediatr Blood Cancer ; 66(1): e27402, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30294914

RESUMO

Treatment of Hodgkin lymphoma (HL) has advanced over time, rendering a fatal disease now largely curable. Multiagent chemotherapy regimens, hematopoietic stem cell transplantation, and radiotherapy are the mainstays of care. Surgical intervention is rarely indicated other than for biopsy at diagnosis. However, for patients with recurrent relapsed HL isolated to one anatomical location, refractory to all other therapy, there may be a beneficial role for surgical excision. Herein, we report the surgical management of three relapsed patients with stage IVB HL who were refractory to multiple other therapeutic approaches, who all achieved good event-free survival after operative management.


Assuntos
Doença de Hodgkin/cirurgia , Recidiva Local de Neoplasia/cirurgia , Terapia de Salvação , Procedimentos Cirúrgicos Operatórios/métodos , Adolescente , Criança , Feminino , Doença de Hodgkin/patologia , Humanos , Recidiva Local de Neoplasia/patologia , Prognóstico
5.
Ultramicroscopy ; 192: 7-13, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29800934

RESUMO

The scanning helium microscope (SHeM) is a new addition to the array of available microscopies, particularly for delicate materials that may suffer damage under techniques utilising light or charged particles. As with all other microscopies, the specifics of image formation within the instrument are required to gain a full understanding of the produced micrographs. We present work detailing the basics of the subject for the SHeM, including the specific nature of the projection distortions that arise due to the scattering geometry. Extension of these concepts allowed for an iterative ray tracing Monte Carlo model replicating diffuse scattering from a sample surface to be constructed. Comparisons between experimental data and simulations yielded a minimum resolvable step height of (67 ±â€¯5) µm and a minimum resolvable planar angle of (4.3 ±â€¯0.3)° for the instrument in question.

6.
Soc Sci Med ; 183: 80-87, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28475902

RESUMO

The Extending Working Lives (EWL) agenda seeks to sustain employment up to and beyond traditional retirement ages. This study examined the potential role of childhood factors in shaping labour force participation and exit among older adults, with a view to informing proactive interventions early in the life-course to enhance individuals' future capacity for extending their working lives. Childhood adversity and socioeconomic disadvantage have previously been linked to ill-health across the life-span and sickness benefit in early adulthood. This study builds upon previous research by examining associations between childhood adversity and self-reported labour force participation among older adults (aged 55). Data was from the National Child Development Study - a prospective cohort of all English, Scottish, & Welsh births in one week in 1958. There was evidence for associations between childhood adversity and increased risk of permanent sickness at 55 years - which were largely sustained after adjustment for educational disengagement and adulthood factors (mental/physical health, qualifications, socioeconomic disadvantage). Specifically, children who were abused or neglected were more likely to be permanently sick at 55 years. In addition, among males, those in care, those experiencing illness in the home, and those experiencing two or more childhood adversities were more likely to be permanently sick at 55 years. Childhood factors were also associated with part-time employment and retirement at 55 years. Severe childhood adversities may represent important distal predictors of labour force exit at 55 years, particularly via permanent sickness. Notably, some adversities show associations among males only, which may inform interventions designed to extend working lives.


Assuntos
Maus-Tratos Infantis/psicologia , Saúde da Criança/normas , Emprego/psicologia , Aposentadoria/psicologia , Classe Social , Criança , Maus-Tratos Infantis/reabilitação , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Aposentadoria/normas , Reino Unido , Engajamento no Trabalho , Recursos Humanos
7.
Soc Sci Med ; 177: 27-34, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28157566

RESUMO

Housing is a significant determinant of health and substandard housing is a public health issue. East London has long had a shortage of social and affordable housing, worsened in recent years by a combination of stressors. In one of East London's most deprived boroughs, Newham, changes brought about by the 2011 Localism Act and the unique demands of being the host Olympic borough in 2012 have brought considerable pressures to bear on social infrastructure. This paper examines how these pressures were experienced by local residents via their narratives of social housing and health. The data reported here are from a qualitative study comprising two waves of data collection. Narrative family interviews and go-along interviews were conducted with 40 Newham residents at wave one and 28 at wave two. A narrative analysis with a Bakhtinian interpretation was undertaken. This revealed that residents framed experiences of social housing in terms of an inherent system-level ideology based on notions of need and waiting. A particularly striking feature of this ideology was the extent to which descriptions of ill health and impairment were implicated in constructions of housing need; participants directly attributed a range of health complaints to their housing predicaments, including stress, depression, cancer scares, panic attacks and loss of sleep. Understanding the contested ideology of social housing can illuminate both the dynamic processes of social exclusion and the ways in which its subjects seek to resist it.


Assuntos
Nível de Saúde , Habitação/tendências , Narração , Percepção , Adulto , Feminino , Humanos , Renda/tendências , Londres/etnologia , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Grupos Raciais/psicologia , Grupos Raciais/estatística & dados numéricos , Fatores Sexuais , Fatores Sociológicos
8.
Rev Sci Instrum ; 87(5): 053301, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27250408

RESUMO

A simple design for an inexpensive, cooled, free-jet beam source is described. The source assembly features an integrated cooling system as supplied by a counter-flow of chilled nitrogen, and is composed primarily of off-the-shelf tube fittings. The design facilitates rapid implementation and eases subsequent alignment with respect to any downstream beamline aperture. The source assembly outlined cools the full length of the stagnation volume, offering temperature control down to 100 K and long-term temperature stability better than ±1 K.

9.
Ann R Coll Surg Engl ; 98(3): e45-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26890849

RESUMO

We describe a patient who presented with acute small bowel obstruction five years after Roux-en-Y reconstruction. Computed tomography and operative exploration showed a retrograde intussusception at the gastrojejunostomy due to an intraluminal suture concretion. We describe the preoperative imaging, endoscopic and intraoperative findings, and review the literature.


Assuntos
Derivação Gástrica/efeitos adversos , Intussuscepção , Doenças do Jejuno , Gastropatias , Adulto , Feminino , Humanos , Intussuscepção/etiologia , Intussuscepção/cirurgia , Doenças do Jejuno/etiologia , Doenças do Jejuno/cirurgia , Gastropatias/etiologia , Gastropatias/cirurgia
10.
Nat Commun ; 7: 10189, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26727303

RESUMO

Delicate structures (such as biological samples, organic films for polymer electronics and adsorbate layers) suffer degradation under the energetic probes of traditional microscopies. Furthermore, the charged nature of these probes presents difficulties when imaging with electric or magnetic fields, or for insulating materials where the addition of a conductive coating is not desirable. Scanning helium microscopy is able to image such structures completely non-destructively by taking advantage of a neutral helium beam as a chemically, electrically and magnetically inert probe of the sample surface. Here we present scanning helium micrographs demonstrating image contrast arising from a range of mechanisms including, for the first time, chemical contrast observed from a series of metal-semiconductor interfaces. The ability of scanning helium microscopy to distinguish between materials without the risk of damage makes it ideal for investigating a wide range of systems.

11.
Health Place ; 36: 18-24, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26340644

RESUMO

Mega-sporting event regeneration, as a specific approach to urban renewal, uses impending host-city status as a catalyst for revitalisation and has the potential to improve health both through addressing deprivation and by promoting increased sport and physical activity among the host-city's population. This qualitative study explored how hosting of the London 2012 Games impacted upon the way East London residents perceived and experienced the social determinants of health in their local neighbourhood. We conducted narrative family interviews, go-along interviews and video focus group workshops with 66 Newham residents, aged 12-55 years, immediately after the Games. A narrative analytic approach examined accounts of health and wellbeing experiences in terms of neighbourhood change and the spectacle of the Games. Participants of this qualitative study generally welcomed the respite and the unexpected chance to live in a cleaner, safer and more unified environment. However, this positivity was underscored by an acute awareness that this was a very temporary situation and one that was intended to support the event rather than residents.


Assuntos
Aniversários e Eventos Especiais , Determinantes Sociais da Saúde , Esportes , Reforma Urbana , Adulto , Feminino , Humanos , Entrevistas como Assunto , Londres , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Adulto Jovem
12.
Rev Sci Instrum ; 86(2): 023704, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25725849

RESUMO

We present a scanning helium microscope equipped to make use of the unique contrast mechanisms, surface sensitivity, and zero damage imaging the technique affords. The new design delivers an order of magnitude increase in the available helium signal, yielding a higher contrast and signal-to-noise ratio. These improvements allow the microscope to produce high quality, intuitive images of samples using topological contrast, while setting the stage for investigations into further contrast mechanisms.

13.
Eur J Neurol ; 20(1): 71-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22681045

RESUMO

BACKGROUND AND PURPOSE: Intracranial haemorrhage in neurosarcoidosis (NS-ICH) is rare, poorly understood and the diagnosis of NS may not be immediately apparent. METHODS: The clinical features of three new NS-ICH cases are described including new neuropathological findings and collated with cases from a systematic literature review. CASES: (i) A 41-year-old man with headaches, hypoandrogenism and encephalopathy developed a cerebellar haemorrhage. He had neuropathological confirmation of NS with biopsy-proven angiocentric granulomata and venous disruption. He responded to immunosuppressive therapy. (ii) A 41-year-old man with no history of hypertension was found unconscious. A subsequently fatal pontine haemorrhage was diagnosed. Liver biopsy revealed sarcoid granulomas. (iii) A 36-year-old man with raised intracranial pressure headaches presented with a seizure and a frontal haemorrhage. Hilar lymph node biopsy confirmed sarcoidosis, and he was treated successfully. Systematic review: Twelve other published cases were identified and collated with our cases. Average age was 36 years and M:F = 2.3:1; 46% presented with neurological symptoms and 31% had CNS-isolated disease. Immediate symptoms of ICH were acute/worsening headache or seizures (60%). ICH was supratentorial (62%), infratentorial (31%) or subarachnoid (7%). Forty percent had definite NS, 53% probable NS and 7% possible NS (Zajicek criteria). Antigranulomatous/immunosuppressive therapy regimens varied and 31% died. CONCLUSIONS: This series expands our knowledge of the pathology of NS-ICH, which may be of arterial or venous origin. One-third have isolated NS. Clinicians should consider NS in young-onset ICH because early aggressive antigranulomatous therapy may improve outcome.


Assuntos
Doenças do Sistema Nervoso Central/complicações , Hemorragias Intracranianas/diagnóstico , Hemorragias Intracranianas/etiologia , Sarcoidose/complicações , Adulto , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X
14.
Nurs Stand ; 25(50): 42-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21928590

RESUMO

AIM: To evaluate clinical competence assessment in pre-registration BSc nursing programmes in one geographical area in the Republic of Ireland. METHOD: A mixed method approach comprising focus group interviews and survey questionnaires was used. The sample comprised preceptors and nursing students across three disciplines of nursing--general, mental health and intellectual (learning) disability. Methods of analysis were thematic analysis and the Statistical Package for Social Sciences (SPSS) (Version 15). RESULTS: Students' and preceptors' views of competence assessment and the process of competence assessment are reported. The study focused on language complexity, the assessment framework, the amount of time allocated for interviews and achievement of purpose. The main conclusions were that language needs to be user-friendly, the process needs to be easy to follow and all aspects of clinical competence must be assessed. The response rate from students was 87% but the preceptor response rate was lower (30%). CONCLUSION: Competence based assessment in the clinical environment is a core component of pre-registration nurse education programmes. Competing demands in the clinical environment challenge both the student and preceptor during the competence assessment process.


Assuntos
Competência Clínica , Grupos Focais , Irlanda , Preceptoria , Estudantes de Enfermagem , Inquéritos e Questionários
15.
Ir J Med Sci ; 179(3): 427-30, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20585896

RESUMO

BACKGROUND: Most cases of cervical cancer are associated with human papillomavirus (HPV) types 16 and 18. This study examined the effect of message framing on mother's intentions to obtain HPV vaccination for their teenage daughters and investigated predictors of HPV vaccination intentions. METHODS: Seventy-two mothers of daughters in the 8-16-year age group were randomly assigned to read either a gain-framed (describing the benefits of receiving the vaccine) or a loss-framed (describing the costs of not receiving the vaccine) message and completed measures assessing their intention to have their daughter/s vaccinated, normative beliefs, attitudes and perceived behavioural control. CONCLUSIONS: Awareness of HPV was low but intentions to vaccinate were high. There was no effect of message frame on vaccination intentions. Attitudes towards HPV vaccination and the influence of both peers and medical professionals are important factors in HPV vaccine acceptability.


Assuntos
Comportamentos Relacionados com a Saúde , Mães , Vacinas contra Papillomavirus/uso terapêutico , Vacinação/estatística & dados numéricos , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Papillomavirus/prevenção & controle , Neoplasias do Colo do Útero/virologia
16.
J Appl Microbiol ; 106(1): 317-28, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19120616

RESUMO

AIMS: To investigate the factors affecting benzene biodegradation and microbial community composition in a contaminated aquifer. METHODS AND RESULTS: We identified the microbial community in groundwater samples from a benzene-contaminated aquifer situated below a petrochemical plant. Eleven out of twelve groundwater samples with in situ dissolved oxygen concentrations between 0 and 2.57 mg l(-1) showed benzene degradation in aerobic microcosm experiments, whereas no degradation in anaerobic microcosms was observed. The lack of aerobic degradation in the remaining microcosm could be attributed to a pH of 12.1. Three groundwaters, examined by 16S rRNA gene clone libraries, with low in situ oxygen concentrations and high benzene levels, each had a different dominant aerobic (or denitrifying) population, either Pseudomonas, Polaromonas or Acidovorax species. These groundwaters also had syntrophic organisms, and aceticlastic methanogens were detected in two samples. The alkaline groundwater was dominated by organisms closely related to Hydrogenophaga. CONCLUSIONS: Results show that pH 12.1 is inimical to benzene biodegradation, and that oxygen concentrations below 0.03 mg l(-1) can support aerobic benzene-degrading communities. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings will help to guide the treatment of contaminated groundwaters, and raise questions about the extent to which aerobes and anaerobes may interact to effect benzene degradation.


Assuntos
Bactérias Aeróbias/isolamento & purificação , Bactérias Anaeróbias/isolamento & purificação , Benzeno/metabolismo , Biodegradação Ambiental , Microbiologia da Água , Bactérias Aeróbias/genética , Bactérias Aeróbias/metabolismo , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/metabolismo , DNA Bacteriano/genética , Concentração de Íons de Hidrogênio , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
17.
Lett Appl Microbiol ; 47(1): 60-6, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18544140

RESUMO

AIMS: To isolate benzene-degrading strains from neutral and alkaline groundwaters contaminated by benzene, toluene, ethylbenzene, xylenes (BTEX) from the SIReN aquifer, UK, and to test their effective pH range and ability to degrade TEX. METHODS AND RESULTS: The 14 isolates studied had an optimum pH for growth of 8, and could degrade benzene to below detection level (1 microg l(-1)). Five Rhodococcus erythropolis strains were able to metabolize benzene up to pH 9, two distinct R. erythropolis strains to pH 10, and one Arthrobacter strain to pH 8.5. These Actinobacteria also degraded benzene at least down to pH 5.5. Six other isolates, a Hydrogenophaga and five Pseudomonas strains, had a narrower pH tolerance for benzene degradation (pH 6 to 8.5), and could metabolize toluene; in addition, the Hydrogenophaga and two Pseudomonas strains utilized o-, m- or p-xylenes. None of these strains degraded ethylbenzene. CONCLUSIONS: Phylogenetically distinct isolates, able to degrade BTX compounds, were obtained, and some degraded benzene at high pH. SIGNIFICANCE AND IMPACT OF THE STUDY: High pH has previously been found to inhibit in situ degradation of benzene, a widespread, carcinogenic groundwater contaminant. These benzene-degrading organisms therefore have potential applications in the remediation or natural attenuation of alkaline waters.


Assuntos
Álcalis/farmacologia , Bactérias/isolamento & purificação , Benzeno/metabolismo , Microbiologia da Água , Bactérias/metabolismo , Bactérias Aeróbias/crescimento & desenvolvimento , Bactérias Aeróbias/metabolismo , Biodegradação Ambiental , Xilenos/metabolismo
18.
Lasers Surg Med ; 13(3): 312-20, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8515670

RESUMO

Heat-induced oxygen tension changes in RIF-1 tumors in C3H male mice were analyzed in an attempt to correlate these changes with tumor response to Nd:YAG laser heating. A low power, microprocessor-controlled Nd:YAG laser was used to superficially heat 250-300 mm3 tumors to base temperatures of 44, 45, 46, or 48 degrees C for 30 minutes via a flexible 600 microns quartz fiberoptic with a terminating microlens. A glass, Clark-style microelectrode was inserted into the center of each tumor allowing real time measurement of the tumor's oxygenation status before, during, and after heating. Results showed that heating at 44 degrees C caused a greater than 2-fold increase in oxygen tension during heating, while a temperature of 48 degrees C caused a brief initial increase in oxygen tension followed by a decrease to below pretreatment values. There was a significant correlation (P < 0.05) between relative tumor oxygen tension during and post-heating and tumor growth delay. A significant correlation (P < 0.05) was also seen between tumor base temperature during heating and tumor growth delay. It appears from our initial data that single point oxygen tension measurements in small RIF-1 tumors may be useful indicators of this model's response to Nd:YAG laser heating. This result may allow for modification of heating parameters (temperature/time) during treatment to optimize thermal response.


Assuntos
Fibrossarcoma/metabolismo , Hipertermia Induzida/métodos , Terapia a Laser , Consumo de Oxigênio , Neoplasias Cutâneas/metabolismo , Silicatos de Alumínio , Animais , Fibrossarcoma/patologia , Fibrossarcoma/terapia , Temperatura Alta , Hipertermia Induzida/instrumentação , Masculino , Camundongos , Camundongos Endogâmicos C3H , Microeletrodos , Neodímio , Indução de Remissão , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/terapia , Termômetros , Fatores de Tempo , Ítrio
19.
J Hand Surg Br ; 12(1): 120-2, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3033105

RESUMO

Two cases of eccrine tumour of sweat gland origin found in the hand are presented. They were non-tender rounded masses of eight months to two years duration, beneath and adherent to the epidermis but movable on underlying tissue. The pre-operative diagnosis in each case was that of a sebaceous cyst. Histology revealed one to be an eccrine spiradenoma and the other a chondroid syringoma. The lesions were considered unusual in that such tumours usually occur on the trunk, head and back and are rarely found in the hand.


Assuntos
Adenoma de Glândula Sudorípara/patologia , Mãos , Neoplasias das Glândulas Sudoríparas/patologia , Glândulas Sudoríparas/patologia , Adulto , Feminino , Humanos
20.
Br J Surg ; 67(11): 809-10, 1980 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7000226

RESUMO

A prospective placebo controlled randomized trial was carried out in 104 patients with a presumptive diagnosis of acute appendicitis. A single dose of 1 g of metronidazole was given intra-rectally 1 h preoperatively. There were 16 wound infections, 15 (out of 50) in the placebo group, 1 (out of 54) in the metronidazole group. This study supports the already accepted value of metronidazole but suggests that a single intra-rectal dose regimen is adequate for prophylaxis.


Assuntos
Apendicectomia , Metronidazol/uso terapêutico , Pré-Medicação , Infecção da Ferida Cirúrgica/prevenção & controle , Adolescente , Adulto , Idoso , Criança , Ensaios Clínicos como Assunto , Emergências , Feminino , Humanos , Masculino , Metronidazol/administração & dosagem , Pessoa de Meia-Idade , Distribuição Aleatória , Reto , Supositórios
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