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1.
J Eur Acad Dermatol Venereol ; 36(12): 2316-2324, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35920758

RESUMO

Atopic dermatitis (AD) is a chronic inflammatory disease, driven by type 2 inflammation. The condition manifests as moderate-to-severe disease in approximately 20% of adults with AD across Europe and is associated with a substantial burden on patients, society and healthcare systems. However, systematic assessments capturing the totality of disease burden associated with moderate-to-severe AD are limited; therefore, the overall impacts of the disease may be underestimated. A systematic literature review (SLR) was carried out to assess the overall costs of moderate-to-severe AD across Europe, including the financial, societal and humanistic impacts. PubMed, Embase and Cochrane databases were searched to identify relevant studies published between 1 January 2010 and 2 June 2020. Scientific conference proceedings, health technology assessment websites and patient association group websites were also searched for relevant information. Twenty-seven publications, corresponding to 22 unique studies, were included in the analysis. Total costs (direct and productivity losses) reached €20 695 per-person-per-year (PPPY) for adults with uncontrolled symptoms of moderate-to-severe AD. Direct medical costs ranged between €307 and €6993 PPPY; prescription medications and specialist dermatologist visits were the main contributors. Costs increased with disease severity or with uncontrolled disease. Patients with AD also incurred personal costs of €927 per year for healthcare items not reimbursed, which increased by 9% for those with moderate-to-severe forms. Annual work productivity losses comprised most of the total costs reported for adults with moderate-to-severe AD (up to 60.8% of the total burden) and were highest in those with uncontrolled disease (€13 702 PPPY). Patients with moderate-to-severe disease also experienced physical, emotional, and social impacts. The overall costs of moderate-to-severe AD greatly impact on healthcare systems, patients and society. Sustained control of moderate-to-severe AD, through effective treatment and care management, is essential to limit the burden caused by the disease.


Assuntos
Dermatite Atópica , Desempenho Profissional , Adulto , Humanos , Dermatite Atópica/tratamento farmacológico , Efeitos Psicossociais da Doença , Índice de Gravidade de Doença , Europa (Continente) , Custos de Cuidados de Saúde
2.
Rhinology ; 60(4): 252-260, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35230356

RESUMO

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic condition that can adversely affect quality of life for patients. There is no cure for CRSwNP, and patients may require intermittent systemic corticosteroids (SCS) and surgery in addition to intranasal treatment throughout their lifetime. This places a significant burden on the NHS which can be compounded by comorbid conditions such as asthma or NSAID-exacerbated respiratory disease (NERD). Patients with comorbidities are likely to experience higher rates of surgery and more secondary care visits. The aim of this study was to evaluate revision rates and the associated burden for patients with CRSwNP undergoing surgery and compare this to sub-cohorts of patients with comorbidities. MATERIALS AND METHODS: This study has utilised the Hospital Episodes Statistics (HES) database across a ten-year time period (April 2010 to March 2020) to investigate the NHS resource use attributable to CRSwNP for all patients with the condition who have undergone sinus surgery, and to examine the burden of clinically relevant sub-groups. RESULTS: Our results showed that 101,054 patients underwent at least one sinus surgery in relation to their nasal polyps, with Kaplan Meier survival analysis estimating that the 10-year probability of revision is between 71-90% for comorbid patients, and 51% for non-comorbid patients. Patients with a relevant comorbid condition in addition to their CRSwNP were up to 4.7 times more likely to undergo at least one revision surgery during the ten-year analytical time window when compared to patients without a comorbidity. Further to this, comorbid patients had a higher tariff associated with their CRSwNP care across the analytical time window and were therefore likely to be more costly to the healthcare system. CONCLUSIONS: In conclusion, this study demonstrates that there is a high burden attached to CRSwNP-related sinus surgery and that comorbidities are a key driver of NHS resource use.


Assuntos
Pólipos Nasais , Rinite , Sinusite , Doença Crônica , Comorbidade , Humanos , Pólipos Nasais/complicações , Pólipos Nasais/epidemiologia , Pólipos Nasais/cirurgia , Qualidade de Vida , Rinite/complicações , Rinite/epidemiologia , Rinite/cirurgia , Atenção Secundária à Saúde , Sinusite/complicações , Sinusite/epidemiologia , Sinusite/cirurgia
3.
Ulster Med J ; 90(2): 70-76, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34276083

RESUMO

BACKGROUND: Dupilumab, a monoclonal antibody against interleukin (IL)-4 receptor alpha that inhibits IL-4/IL-13 signalling is indicated in dermatology for the treatment of moderate-to-severe atopic dermatitis (AD) in adult and adolescent patients 12 years and older and severe AD in children 6-11 years, who are candidates for systemic therapy. Dupilumab received Early Access to Medicines Scheme (EAMS) approval for adults in March 2017. OBJECTIVES: The purpose of this study was to assess the efficacy outcomes of treatment with dupilumab in EAMS. METHODS: A retrospective analysis of adult patients enrolled in the dupilumab EAMS in the UK. Scores were assessed at baseline and follow up, including the Eczema Area and Severity Index (EASI), Investigator's Global Assessment Score (IGA) and Dermatology Life Quality Index (DLQI). RESULTS: Data were available for 57 adult patients treated with dupilumab for at least 12 weeks; 73.6% of patients had received prior treatment with 3 or 4 immunosuppressants. Baseline scores for the EASI and DLQI were 27.93 (standard deviation, SD 13.09) and 18.26 (SD 6.18) respectively. AD severity scores showed statistically significant improvement at week 16±4 weeks (p <0.001 for all). The mean change in EASI was 14.13 points with 66.7% and 36.7% achieving a 50% (EASI-50) and 75% (EASI-75) improvement in EASI, respectively at 16+/- 4 weeks. IGA scores improved by at least two categories for 75% patients. DLQI scores decreased by a mean of 9.0 points, with 80% patients demonstrating a MCID 4-point improvement. For 85% patients, clinicians rated the treatment response as being either 'better' (19%) or 'much better' (65%). CONCLUSIONS: Dupilumab is associated with a significant and clinically relevant improvements in AD as measured by patient- and physician-reported outcome measures. Importantly, the clinical efficacy, despite the refractory disease of this EAMS cohort, is comparable to that previously reported in clinical trials.


Assuntos
Dermatite Atópica , Eczema , Adolescente , Adulto , Anticorpos Monoclonais Humanizados , Criança , Dermatite Atópica/tratamento farmacológico , Método Duplo-Cego , Acessibilidade aos Serviços de Saúde , Humanos , Injeções Subcutâneas , Estudos Retrospectivos , Índice de Gravidade de Doença , Resultado do Tratamento , Reino Unido
4.
J Radiol Prot ; 41(2)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33571976

RESUMO

A study has been carried out to experimentally determine the calibration factor (CF) of the passive bronchial dosimeter, which consists of a direct radon progeny sensor capped with a 100-wire mesh. First, the CF was determined in controlled environmental conditions simulated in a calibration chamber. With aerosol concentrations varying from 104p cm-3to 105p cm-3and relative humidity varying from 60% to 80% in the chamber, CF was observed to be nearly constant with an average value of (3.8 ± 0.5) × 10-3mSv tracks-1cm2. Then, the CF was determined in real indoor environments in which it was again observed to be almost constant and the mean value was found to be (5.6 ± 0.1) × 10-3mSv tracks-1cm2. Pooling all the data on CFs obtained under controlled conditions and in real indoor environments, a lognormal distribution of the CF was observed with a geometric mean and geometric standard deviation of 0.0052 mSv tracks-1cm2and 1.28 respectively. The experimentally determined value of CF was found to be in close agreement with the theoretically estimated value, taking into consideration the unattached fraction of radon progeny. This dosimeter is passive, cheap, lightweight and, moreover, the CF being stable against environmental variations, will be useful in monitoring inhalation doses due to radon progeny for occupational workers.


Assuntos
Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Monitoramento de Radiação , Radônio , Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Humanos , Dosímetros de Radiação , Radônio/análise , Produtos de Decaimento de Radônio/análise , Telas Cirúrgicas
5.
J Family Med Prim Care ; 9(9): 4736-4740, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33209792

RESUMO

BACKGROUND AND AIMS: Depression accounts for the greatest burden of all mental health problems, and is expected to become the second-highest among all health problems by 2020. Postpartum depression (PPD) is a major public health problem with a peak incidence at 4-6 weeks postpartum, affecting 22% of women within a year of childbirth in India. It has an impact on the mother, her partner, the family, mother-baby bonding and the long-term emotional and cognitive development of the baby. The aim of the study was to: 1.To find out the prevalence of depression among women during the postpartum period 2.To identify the factors associated with depressive symptoms among them. METHODS: A cross-sectional study was conducted in an urban slum of Bhubaneswar from July 2017 to January 2018, among a sample of 60 postnatal mothers who had delivered in the last six months; selected by simple random sampling technique. Edinburgh Postnatal depression scale (EPDS) was used to identify mothers at risk of postnatal depression. A score of ≥13 was considered as positive for depressive symptoms. RESULTS: The prevalence of PPD was found to be 8.57%. Religion was found to be a statistically significant factor associated with PPD. Other factors like literacy status, socio-economic status, high parity, sex of the newborn, mode of delivery were also found to have an association with PPD. CONCLUSION: This study identified certain socio-demographic and obstetric risk factors for postnatal depressive symptoms in a community setting of an urban slum; screening of risk factors will help in designing preventive strategies for identifying PPD.

6.
J Environ Radioact ; 214-215: 106175, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32063292

RESUMO

In the present study, thoron exhalation flux density were measured in the soil samples collected around the Indian station namely Bharati (69° 24.41' S, 76° 11.72' E) and its nearby islands in the Larsemann hills region of Antarctica. Further, dependency of thoron mass emanation rate and emanation coefficient on the soil grain size was studied by segregating the soil samples into four different grain size groups: 50-100 µm, 100-200 µm, 200-500 µm and 500-1000 µm which showed that both of them follow a decreasing trend with increase in grain size. A comparison of measured mass emanation rate between different soil samples showed that it had a larger variation for the smaller grain size which eventually decreased as grain size increased while emanation coefficient was observed to be nearly constant for all the grain size groups. The variation in emanation coefficient with respect to mean grain size has been investigated and an empirical exponential model has been proposed for predicting emanation coefficient for different grain sizes.


Assuntos
Monitoramento de Radiação , Solo , Regiões Antárticas , Expiração , Radônio
7.
J Radiol Prot ; 37(2): 379-389, 2017 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-28418936

RESUMO

Experiments have been carried out using the deposition-based Direct Thoron Progeny Sensors (DTPS) in a thoron experimental house. The objective was to study the thoron decay product characteristics such as the deposition velocities, spatial variability and dependence on aerosol particle concentrations. Since the deposition velocity is an important characteristic in the calibration of the DTPS, it is very important to study its dependence on aerosol concentration in a controlled environment. At low aerosol concentration (1500 particles/cm3) the mean effective deposition velocity was measured to be 0.159 ± 0.045 m h-1; at high aerosol concentration (30 000 particles/cm3) it decreased to 0.079 ± 0.009 m h-1. The deposition velocity for the attached fraction of the thoron decay products did not change with increasing aerosol concentration, showing measurement results of 0.048 ± 0.005 m h-1 and 0.043 ± 0.014 m h-1, respectively. At low particle concentration, the effective deposition velocity showed large scattering within the room at different distances from center. The attached fraction deposition velocity remained uniform at different distances from the wall. The measurements in the thoron experimental house can be used as a sensitivity test of the DTPS in an indoor environment with changing aerosol concentration. The uniform spatial distribution of thoron decay products was confirmed within the experimental house. This indicates that direct measurement of thoron decay product concentration should be carried out instead of inferring it from thoron gas concentration, which is very inhomogeneous within the experimental house.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Habitação , Monitoramento de Radiação/métodos , Produtos de Decaimento de Radônio/análise , Radônio/análise , Aerossóis , Movimentos do Ar , Calibragem , Exposição Ambiental , Modelos Teóricos
8.
Bone Joint J ; 98-B(10 Supple B): 22-27, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27694512

RESUMO

AIMS: The aim of this to study was to compare the previously unreported long-term survival outcome of the Oxford medial unicompartmental knee arthroplasty (UKA) performed by trainee surgeons and consultants. PATIENTS AND METHODS: We therefore identified a previously unreported cohort of 1084 knees in 947 patients who had a UKA inserted for anteromedial knee arthritis by consultants and surgeons in training, at a tertiary arthroplasty centre and performed survival analysis on the group with revision as the endpoint. RESULTS: The ten-year cumulative survival rate for revision or exchange of any part of the prosthetic components was 93.2% (95% confidence interval (CI) 86.1 to 100, number at risk 45). Consultant surgeons had a nine-year cumulative survival rate of 93.9% (95% CI 90.2 to 97.6, number at risk 16). Trainee surgeons had a cumulative nine-year survival rate of 93.0% (95% CI 90.3 to 95.7, number at risk 35). Although there was no differences in implant survival between consultants and trainees (p = 0.30), there was a difference in failure pattern whereby all re-operations performed for bearing dislocation (n = 7), occurred in the trainee group. This accounted for 0.6% of the entire cohort and 15% of the re-operations. CONCLUSION: This is the largest single series of the Oxford UKA ever reported and demonstrates that good results can be achieved by a heterogeneous group of surgeons, including trainees, if performed within a high-volume centre with considerable experience with the procedure. Cite this article: Bone Joint J 2016;(10 Suppl B):22-7.


Assuntos
Artroplastia do Joelho/métodos , Competência Clínica , Prótese do Joelho , Osteoartrite do Joelho/cirurgia , Idoso , Artroplastia do Joelho/educação , Artroplastia do Joelho/instrumentação , Artroplastia do Joelho/normas , Consultores , Educação de Pós-Graduação em Medicina , Inglaterra , Feminino , Humanos , Tábuas de Vida , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Falha de Prótese , Reoperação/métodos , Reoperação/estatística & dados numéricos , Análise de Sobrevida , Centros de Atenção Terciária/normas , Centros de Atenção Terciária/estatística & dados numéricos , Resultado do Tratamento
9.
Rev Sci Instrum ; 87(3): 033504, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27036774

RESUMO

A 17 kJ transportable plasma focus (PF) device with flexible transmission lines is developed and is characterized. Six custom made capacitors are used for the capacitor bank (CB). The common high voltage plate of the CB is fixed to a centrally triggered spark gap switch. The output of the switch is coupled to the PF head through forty-eight 5 m long RG213 cables. The CB has a quarter time-period of 4 µs and an estimated current of 506 kA is delivered to the PF device at 17 kJ (60 µF, 24 kV) energy. The average neutron yield measured using silver activation detector in the radial direction is (7.1 ± 1.4) × 10(8) neutrons/shot over 4π sr at 5 mbar optimum D2 pressure. The average neutron yield is more in the axial direction with an anisotropy factor of 1.33 ± 0.18. The average neutron energies estimated in the axial as well as in the radial directions are (2.90 ± 0.20) MeV and (2.58 ± 0.20) MeV, respectively. The flexibility of the PF head makes it useful for many applications where the source orientation and the location are important factors. The influence of electromagnetic interferences from the CB as well as from the spark gap on applications area can be avoided by putting a suitable barrier between the bank and the PF head.

10.
Radiat Prot Dosimetry ; 171(2): 181-186, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27009245

RESUMO

The decay products of radon and thoron are essentially the radioisotopes of polonium, bismuth and lead, and are solid particulates, which deposit in different parts of the respiratory tract upon inhalation, subsequently emitting high-energy alpha particles upon their radioactive decay. Development of passive deposition-based direct progeny sensors known as direct radon and thoron progeny sensors have provided an easy-to-use technique for time-integrated measurements of the decay products only. These dosemeters are apt for large-scale population dosimetry to assign inhalation doses to the public. The paper gives an insight into the technique, the calibration, comparison with the prevalently used active grab filter paper sampling technique, alpha track diameter analysis in these progeny sensors, progeny deposition velocity measurements carried out using these detector systems in the indoor as well as outdoor environment, and applications of these sensors for time-integrated unattached fraction estimation.


Assuntos
Poluentes Radioativos do Ar/análise , Bismuto/análise , Chumbo/análise , Polônio/análise , Monitoramento de Radiação/métodos , Produtos de Decaimento de Radônio/análise , Radônio/análise , Poluição do Ar em Ambientes Fechados/análise , Calibragem , Meio Ambiente , Habitação , Radiometria/métodos , Fatores de Tempo
11.
J Environ Radioact ; 147: 125-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26065929

RESUMO

In India, High Background Radiation Areas (HBRAs) due to enhanced levels of naturally occurring radionuclides in soil (thorium and, to a lesser extent, uranium), are located along some parts of the coastal tracts viz. the coastal belt of Kerala, Tamilnadu and Odisha. It is conjectured that these deposits will result in higher emissions of radon isotopes ((222)Rn and (220)Rn) and their daughter products as compared to Normal Background Radiation Areas (NBRAs). While the annual external dose rates contributed by gamma radiations in these areas are about 5-10 times higher, the extent of increase in the inhalation dose rates attributable to (222)Rn and (220)Rn and their decay products is not well quantified. Towards this, systematic indoor surveys were conducted wherein simultaneous measurements of time integrated (222)Rn and (220)Rn gas and their decay product concentrations was carried out in around 800 houses in the HBRAs of Kerala and Odisha to estimate the inhalation doses. All gas measurements were carried out using pin-hole cup dosimeters while the progeny measurements were with samplers and systems based on the Direct radon/thoron Progeny sensors (DRPS/DTPS). To corroborate these passive measurements of decay products concentrations, active sampling was also carried out in a few houses. The results of the surveys provide a strong evidence to conclude that the inhalation doses due to (222)Rn and (220)Rn gas and their decay products in these HBRAs are in the same range as observed in the NBRAs in India.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Exposição por Inalação , Exposição à Radiação , Habitação , Índia , Monitoramento de Radiação , Radiometria , Radônio/análise , Produtos de Decaimento de Radônio/análise
12.
J Environ Radioact ; 138: 101-5, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25216466

RESUMO

Assigning indoor radon doses to populations based on the widely used, cumulative radon concentration monitoring techniques is beset with errors arising due to uncertain equilibrium factors and unattached fractions. Moreover, the dose conversion factor (DCF) of radon decay products may vary by a factor of ∼40 within the particle size range from ∼0.5 nm to tens of micrometers. An ideal detector should have a response, which closely mimics the strong dependence of the DCF on the particle size. In this context, we propose a new approach in which the doses are computed directly from the time integrated progeny deposition fluxes on a suitably tailored surrogate surface. The deposition on this wire-mesh capped detector system closely mimics the deposition rate in human respiratory tract. The detection unit consists of an optimally designed wire-mesh capped Direct Radon Progeny Sensor (DRPS) system. Of the different wire-mesh types, 100 mesh types were found to be suitable considering the fine and coarse fraction penetration efficiencies. The calibration factor was theoretically derived as 0.0077 {mSv (Tracks cm(-2))(-1)}, for converting the measured atom flux in the 100-mesh capped DRPS system to inhalation dose attributed to radon progeny.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Exposição por Inalação , Radiometria/métodos , Radônio/análise , Humanos , Tamanho da Partícula , Doses de Radiação , Radiometria/instrumentação , Produtos de Decaimento de Radônio/análise
13.
Radiat Prot Dosimetry ; 162(1-2): 152-6, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25084794

RESUMO

As part of a survey on concentrations of radon, thoron and their decay products in different indoor environments of the Balkan region involving international collaboration, measurements were performed in 43 schools from 5 municipalities of the Republic of Macedonia. The time-integrated radon and thoron gas concentrations (CRn and CTn) were measured by CR-39 (placed in chambers with different diffusion barriers), whereas the equilibrium equivalent radon and thoron concentrations (EERC and EETC) were measured using direct radon-thoron progeny sensors consisting of LR-115 nuclear track detectors. The detectors were deployed at a distance of at least 0.5 m from the walls as well as far away from the windows and doors in order to obtain more representative samples of air from the breathing zone; detectors were exposed over a 3-month period (March-May 2012). The geometric mean (GM) values [and geometric standard deviations (GSDs)] of CRn, CTn, EERC and EETC were 76 (1.7), 12 (2.3), 27 (1.4) and 0.75 Bq m(-3) (2.5), respectively. The equilibrium factors between radon and its decay products (FRn) and thoron and its decay products (FTn (>0.5 m)) were evaluated: FRn ranged between 0.10 and 0.84 and FTn (>0.5 m) ranged between 0.003 and 0.998 with GMs (and GSDs) equal to 0.36 (1.7) and 0.07 (3.4), respectively.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento de Radiação , Radônio/análise , Mapeamento Geográfico , Humanos , Radiometria , República da Macedônia do Norte , Instituições Acadêmicas , Fatores de Tempo
14.
Osteoarthritis Cartilage ; 22(2): 334-43, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24361742

RESUMO

OBJECTIVE: To identify osteoarthritis (OA) relevant genes and pathways in damaged and undamaged cartilage isolated from the knees of patients with anteromedial gonarthrosis (AMG) - a specific form of knee OA. DESIGN: Cartilage was obtained from nine patients undergoing unicompartmental knee replacement (UKR) for AMG. AMG provides a spatial representation of OA progression; showing a reproducible and histologically validated pattern of cartilage destruction such that damaged and undamaged cartilage from within the same knee can be consistently isolated and examined. Gene expression was analysed by microarray and validated using real-time PCR. RESULTS: Damaged and undamaged cartilage showed distinct gene expression profiles. 754 genes showed significant up- or down-regulation (non-False discovery rate (FDR) P < 0.05) with enrichment for genes involved in cell signalling, Extracellular Matrix (ECM) and inflammatory response. A number of genes previously unreported in OA showed strongly altered expression including RARRES3, ADAMTSL2 and DUSP10. Confirmation of genes previously identified as modulated in OA was also obtained e.g., SFRP3, MMP3 and IGF1. CONCLUSIONS: This is the first study to examine a common and consistent phenotype of OA to allow direct comparison of damaged and undamaged cartilage from within the same joint compartment. We have identified specific gene expression profiles in damaged and undamaged cartilage and have determined relevant genes and pathways in OA progression. Importantly this work also highlights the necessity for phenotypic and microanatomical characterization of cartilage in future studies of OA pathogenesis and therapeutic development.


Assuntos
Cartilagem Articular/metabolismo , Osteoartrite do Joelho/genética , Transcriptoma/fisiologia , Idoso , Artroplastia do Joelho , Progressão da Doença , Feminino , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/fisiologia , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Osteoartrite do Joelho/metabolismo , Osteoartrite do Joelho/cirurgia , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real/métodos
15.
Rev Sci Instrum ; 84(6): 063503, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23822341

RESUMO

Development of a palm top plasma focus device generating (5.2 ± 0.8) × 10(4) neutrons∕pulse into 4π steradians with a pulse width of 15 ± 3 ns is reported for the first time. The weight of the system is less than 1.5 kg. The system comprises a compact capacitor bank, a triggered open air spark gap switch, and a sealed type miniature plasma focus tube. The setup is around 14 cm in diameter and 12.5 cm in length. The energy driver for the unit is a capacitor bank of four cylindrical commercially available electrolytic capacitors. Each capacitor is of 2 µF capacity, 4.5 cm in diameter, and 9.8 cm in length. The cost of each capacitor is less than US$ 10. The internal diameter and the effective length of the plasma focus unit are 2.9 cm and 5 cm, respectively. A DC to DC converter power supply powered by two rechargeable batteries charges the capacitor bank to the desired voltage and also provides a trigger pulse of -15 kV to the spark gap. The maximum energy of operation of the device is 100 J (8 µF, 5 kV, 59 kA) with deuterium gas filling pressure of 3 mbar. The neutrons have also been produced at energy as low as 36 J (3 kV) of operation. The neutron diagnostics are carried out with a bank of (3)He detectors and with a plastic scintillator detector. The device is portable, reusable, and can be operated for multiple shots with a single gas filling.

16.
J Biomech ; 45(16): 2931-4, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23058868

RESUMO

BACKGROUND: Interest in soft tissue RadioStereometric Analysis (RSA) is rising. Previous studies have attempted to use this technique to analyse anterior cruciate ligament (ACL) graft constructs, and more recently, the movement of soft tissue as a precursor to RSA follow up of rotator cuff repairs. These methods were either prone to large amounts of marker migration, deemed unsuitable for in vivo use or, where alternative markers such as stainless steel sutures were used, lost the inherent accuracy that makes RSA an attractive tool in the first place. We describe a modification of tantalum marker balls that allows for immediate secure fixation to soft tissue in order to accurately analyse stretch and displacement of soft tissues using RSA. METHODS: 1.5mm tantalum marker balls were converted to marker beads by pre-drilling with 0.3mm holes, allowing them to be sutured directly to soft tissue. Using an established ACL graft model, the amount of marker micro-motion was then analysed by RSA after cyclical loading between 20 N and 170 N at 25 Hz for 225,000 cycles. FINDINGS: None of 40 marker beads loosened or became detached after 225,000 cycles. Mean micro-motion of the markers was <0.1mm. Analysis of elastic stretch, plastic stretch and stiffness of the graft model was possible. INTERPRETATION: This method of attachment of tantalum markers to soft tissue is simple, reliable and provides immediate stability. Although further work is required to establish its suitability for in vivo use, this technique could potentially be used in all areas where soft tissue RSA is of interest.


Assuntos
Ligamento Cruzado Anterior/diagnóstico por imagem , Análise Radioestereométrica/métodos , Animais , Ligamento Cruzado Anterior/transplante , Bovinos , Elasticidade , Tantálio , Transplantes
17.
Rev Sci Instrum ; 82(2): 026104, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21361643

RESUMO

Development and operation of a portable and compact pulsed neutron source based on sealed-type plasma focus (PF) device are reported. The unit is the smallest sealed-type neutron producing PF device. The effective volume of the PF unit is 33 cm(3) only. A compact size single capacitor (4 µF) is used as the energy driver. A battery based power supply unit is used for charging the capacitor and triggering the spark gap. The PF unit is operated at 10 kV (200 J) and at a deuterium gas filling pressure of 8 mb. The device is operated over a time span of 200 days and the neutron emissions have been observed for 200 shots without changing the gas in between the shots. The maximum yield of this device is 7.8 × 10(4) neutrons/pulse. Beyond 200 shots the yield is below the threshold (1050 neutrons/pulse) of our (3)He detector. The neutron energy is evaluated using time of flight technique and the value is (2.49 ± 0.27) MeV. The measured neutron pulse width is (24 ± 5) ns. Multishot and long duration operations envisage the potentiality of such portable device for repetitive mode of operation.

18.
Knee ; 18(1): 21-3, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19897370

RESUMO

Accurate preoperative assessment of the patellofemoral joint is especially important in compartment specific knee arthritis. This study aims to show the actual intraoperative grade of patellofemoral cartilage damage that may be reliably detected or excluded by preoperative standard radiographic views. 100 consecutive knees awaiting arthroplasty underwent preoperative lateral and skyline radiographs and were scored using the Ahlback score. Intraoperative cartilage damage was assessed using the Collins score. The sensitivity and specificity were calculated for each grade of cartilage damage. Preoperative anterior knee pain and function were assessed and correlated to the degree of cartilage damage. The lateral radiograph shows poor sensitivity for all grades of disease (0.05-0.23). The skyline shows good sensitivity for grade 4 (large full thickness) damage (0.90) but decreases substantially for grades 1-3 (0.19-0.46). Significantly more people with skyline radiograph joint space narrowing complained of anterior knee pain than those with a normal radiograph (p<0.001). There was only a poor correlation between preoperative anterior pain and intraoperative patellofemoral cartilage damage (r=0.24). The lateral radiograph cannot exclude even large areas of full thickness cartilage damage whereas a normal skyline radiograph can reliably exclude significant (grade 4) patellofemoral disease and should be used in addition to the lateral view.


Assuntos
Artrografia/métodos , Cartilagem Articular/diagnóstico por imagem , Osteoartrite do Joelho/diagnóstico por imagem , Articulação Patelofemoral/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Artrografia/classificação , Artroplastia do Joelho , Cartilagem Articular/patologia , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/cirurgia , Articulação Patelofemoral/cirurgia
19.
J Bone Joint Surg Br ; 92(3): 374-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20190308

RESUMO

With medial unicompartmental osteoarthritis (OA) there is occasionally a full-thickness ulcer of the cartilage on the medial side of the lateral femoral condyle. It is not clear whether this should be considered a contraindication to unicompartmental knee replacement (UKR). The aim of this study was to determine why these ulcers occur, and whether they compromise the outcome of UKR. Case studies of knees with medial OA suggest that cartilage lesions on the medial side of the lateral condyle are caused by impingement on the lateral tibial spine as a result of the varus deformity and tibial subluxation. Following UKR the varus and the subluxation are corrected, so that impingement is prevented and the damaged part of the lateral femoral condyle is not transmitting load. An illustrative case report is presented. Out of 769 knees with OA of the medial compartment treated with the Oxford UKR, 59 (7.7%) had partial-thickness cartilage loss and 20 (2.6%) had a full-thickness cartilage deficit on the medial side of the lateral condyle. The mean Oxford Knee Score (OKS) at the last follow-up at a mean of four years was 41.9 (13 to 48) in those with partial-thickness cartilage loss and 41.0 (20 to 48) in those with full-thickness loss. In those with normal or superficially damaged cartilage the mean was 39.5 (5 to 48) and 39.7 (8 to 48), respectively. There were no statistically significant differences between the pre-operative OKS, the final review OKS or of change in the score in the various groups. We conclude that in medial compartment OA, damage to the medial side of the lateral femoral condyle is caused by impingement on the tibial spine and should not be considered a contraindication to an Oxford UKR, even if there is extensive full-thickness ulceration of the cartilage.


Assuntos
Artroplastia do Joelho/métodos , Doenças das Cartilagens/etiologia , Articulação do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças das Cartilagens/diagnóstico por imagem , Doenças das Cartilagens/patologia , Cartilagem Articular/patologia , Contraindicações , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/diagnóstico por imagem , Estudos Prospectivos , Radiografia , Reoperação , Resultado do Tratamento , Úlcera/etiologia , Úlcera/patologia
20.
Knee ; 17(3): 196-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20133136

RESUMO

Revision is the gold standard outcome measurement for survival analyses of orthopaedic implants but reliance on revision as an endpoint has been recently questioned. This study, that assesses long-term outcome in a specific group of patients who had undergone total knee replacement (TKR) for osteoarthritis, highlights the main problems facing modern survival analyses. Minimum 12-year survival and outcome data were reviewed for a series of sixty patients under the age of 60 years (mean age 55.4 years) who underwent total knee replacement (TKR) for osteoarthritis. The patients are a subgroup from a larger consecutive series of 1429 patients who underwent TKR between 1987 and 1993 at a single institution. Whilst the main study aim was to compare outcome of TKR using different endpoints, the outcome of TKR in this younger subpopulation could also be investigated. With revision as the primary endpoint the survival for TKR was 82.2% (95% CI 17.3). The mean OKS at follow-up (mean 15.7 years) was 30.9. However, many of the 82% of patients who did not undergo revision had a less than satisfactory outcome. 41% of these patients reported modest or severe pain (using the OKS) at final follow-up. A combined endpoint including revision, poor function and significant pain drastically reduced the survival rate for the operation. Survival based on revision alone provides an acceptable but inaccurate impression of outcome in younger TKR patients (under 60 years). A true representation of the success of TKR should include pain and function as endpoints.


Assuntos
Artralgia/prevenção & controle , Artroplastia do Joelho/reabilitação , Recuperação de Função Fisiológica , Fatores Etários , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação , Análise de Sobrevida
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