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1.
Phys Rev E ; 109(4-2): 045105, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38755833

RESUMO

This paper is concerned with the processes of spatial propagation and penetration of turbulence from the regions where it is locally excited into initially laminar regions. The phenomenon has come to be known as "turbulence spreading" and witnessed a renewed attention in the literature recently. Here, we propose a comprehensive theory of turbulence spreading based on fractional kinetics. We argue that the use of fractional-derivative equations permits a general approach focusing on fundamentals of the spreading process regardless of a specific turbulence model and/or specific instability type. The starting point is the Hamiltonian of resonant wave-wave interactions, from which a family of scaling laws for the asymptotic spreading is derived. Both three- and four-wave interactions are considered. The results span from a subdiffusive spreading in the parameter range of weak chaos to avalanche propagation in regimes with population inversion. Attention is paid to how nonergodicity introduces weak mixing, memory and intermittency into spreading dynamics, and how the properties of non-Markovianity and nonlocality emerge from the presence of islands of regular dynamics in phase space. Also we resolve an existing question concerning turbulence spillover into gap regions, where the instability growth is locally suppressed, and show that the spillover occurs through exponential (Anderson-like) localization in case of four-wave interactions and through an algebraic (weak) localization in case of triad interactions. In the latter case an inverse-cubic behavior of the spillover function is found. Wherever relevant, we contrast our findings against the available observational and numerical evidence, and we also commit ourselves to establish connections with the models of turbulence spreading proposed previously.

2.
Scand J Trauma Resusc Emerg Med ; 32(1): 32, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38641643

RESUMO

BACKGROUND: Nonspecific discharge diagnoses after acute hospital courses represent patients discharged without an established cause of their complaints. These patients should have a low risk of adverse outcomes as serious conditions should have been ruled out. We aimed to investigate the mortality and readmissions following nonspecific discharge diagnoses compared to disease-specific diagnoses and assessed different nonspecific subgroups. METHODS: Register-based cohort study including hospital courses beginning in emergency departments across 3 regions of Denmark during March 2019-February 2020. We identified nonspecific diagnoses from the R- and Z03-chapter in the ICD-10 classification and excluded injuries, among others-remaining diagnoses were considered disease-specific. Outcomes were 30-day mortality and readmission, the groups were compared by Cox regression hazard ratios (HR), unadjusted and adjusted for socioeconomics, comorbidity, administrative information and laboratory results. We stratified into short (3-<12 h) or lengthier (12-168 h) hospital courses. RESULTS: We included 192,185 hospital courses where nonspecific discharge diagnoses accounted for 50.7% of short and 25.9% of lengthier discharges. The cumulative risk of mortality for nonspecific vs. disease-specific discharge diagnoses was 0.6% (0.6-0.7%) vs. 0.8% (0.7-0.9%) after short and 1.6% (1.5-1.7%) vs. 2.6% (2.5-2.7%) after lengthier courses with adjusted HRs of 0.97 (0.83-1.13) and 0.94 (0.85-1.05), respectively. The cumulative risk of readmission for nonspecific vs. disease-specific discharge diagnoses was 7.3% (7.1-7.5%) vs. 8.4% (8.2-8.6%) after short and 11.1% (10.8-11.5%) vs. 13.7% (13.4-13.9%) after lengthier courses with adjusted HRs of 0.94 (0.90-0.98) and 0.95 (0.91-0.99), respectively. We identified 50 clinical subgroups of nonspecific diagnoses, of which Abdominal pain (n = 12,462; 17.1%) and Chest pain (n = 9,599; 13.1%) were the most frequent. The subgroups described differences in characteristics with mean age 41.9 to 80.8 years and mean length of stay 7.1 to 59.5 h, and outcomes with < 0.2-8.1% risk of 30-day mortality and 3.5-22.6% risk of 30-day readmission. CONCLUSIONS: In unadjusted analyses, nonspecific diagnoses had a lower risk of mortality and readmission than disease-specific diagnoses but had a similar risk after adjustments. We identified 509 clinical subgroups of nonspecific diagnoses with vastly different characteristics and prognosis.


Assuntos
Alta do Paciente , Readmissão do Paciente , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Comorbidade , Fatores Socioeconômicos , Estudos Retrospectivos
3.
Ugeskr Laeger ; 185(51)2023 12 18.
Artigo em Dinamarquês | MEDLINE | ID: mdl-38105731

RESUMO

Traumatic fractures are often treated conservatively. Bone healing is a complex process and the complexities of a fracture, bone quality, treatment, and patient factors are all crucial. Routine X-rays and clinical follow-ups are a significant cost to society as well as exposing the patient to increased radiation and should only be performed if there is a risk of complications that may impact the treatment. It is difficult to assess on X-rays alone, whether there is sufficient bone healing and X-rays are therefore always recommended in conjunction with clinical examination.


Assuntos
Fraturas Ósseas , Adulto , Humanos , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/terapia , Radiografia , Exame Físico , Consolidação da Fratura
4.
Clin Epidemiol ; 15: 939-955, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37700929

RESUMO

Infectious diseases are major health care challenges globally and a prevalent cause of admission to emergency departments. Epidemiologic characteristics and outcomes based on population level data are limited. The Database of Community Acquired Infections in Eastern Denmark (DCAIED) 2018-2021 was established with the aim to explore and estimate the population characteristics, and outcomes of patients suffering from community acquired infections at the emergency departments in the Capital Region and the Zealand Region of Denmark using data from electronic medical records. Adult patients (≥18 years) presenting to the emergency department with suspected or confirmed infection are included in the cohort. Presence of sepsis and organ failure are assessed using modified criteria from the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). During the inclusion period from January 2018 to January 2022, 2,241,652 adult emergency department visits have been registered. Of these, 451,825 were unique encounters of which 60,316 fulfilled criteria of suspected infection and 28,472 fulfilled sepsis criteria and 8,027 were defined as septic shock. The database covers the entire Capital and Zealand Region of Denmark with an uptake area of 2.6 million inhabitants and includes demographic, laboratory and outcome indicators, with complete follow-up. The database is well-suited for epidemiological research for future national and international collaborations.

5.
J Am Med Dir Assoc ; 24(12): 1898-1903, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37567243

RESUMO

OBJECTIVES: Older patients are typically underrepresented in clinical trials despite representing a major proportion of the patient population. We aim to describe the feasibility of performing body composition measures, physical function measures, and patient-reported questionnaires within the first 24 hours of admission in a large sample of older acutely admitted medical patients. In addition, we aim to characterize patients with missing measurements. DESIGN: Secondary analyses of cross-sectional data from a cohort study. SETTING AND PARTICIPANTS: A total of 1071 acutely admitted patients aged ≥65 years from the acute medical ward at Bispebjerg Hospital, were enrolled within the first 24 hours of hospitalization. METHODS: Body composition was investigated using direct segmental multifrequency bioelectrical impedance analyses (DSM-BIA) and physical function was assessed using hand grip strength (HGS) and the 30-second sit-to-stand test (STS). The orientation-memory-concentration test (OMC) was used to evaluate the prevalence of cognitive impairments within 24 hours of hospitalization, and the OMC in conjunction with the Strength, Assistance walking, Rise from a chair, Climb stairs, and Falls questionnaire (SARC-F) was used to assess the feasibility of patient-reported outcomes (PROs). RESULTS: Mean age was 78.8 ± 7.8 years (53.0% female). HGS was performed in 96.2% of the enrolled patients, whereas the PRO, 30-second STS, and DSM-BIA were performed in 91.2%, 69.2%, and 59.8% of patients, respectively. The main barrier for performing the 30-second STS and body composition measurements was an inability to mobilize the patient from the hospital bed. CONCLUSIONS AND IMPLICATIONS: The assessment of HGS and PROs show excellent feasibility in clinical research including older patients, even when the patients are enrolled and tested within 24 hours of an acute admission. Assessments of DSM-BIA and the 30-second STS show good feasibility but are less feasible in immobile patients often presenting as more frail, weaker, and cognitively impaired.


Assuntos
Sarcopenia , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Masculino , Estudos de Coortes , Sarcopenia/epidemiologia , Força da Mão , Estudos Transversais , Estudos de Viabilidade , Avaliação Geriátrica
6.
Nat Commun ; 12(1): 5089, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34429424

RESUMO

The current nucleic acid signal amplification methods for SARS-CoV-2 RNA detection heavily rely on the functions of biological enzymes which imposes stringent transportation and storage conditions, high cost and global supply shortages. Here, a non-enzymatic whole genome detection method based on a simple isothermal signal amplification approach is developed for rapid detection of SARS-CoV-2 RNA and potentially any types of nucleic acids regardless of their size. The assay, termed non-enzymatic isothermal strand displacement and amplification (NISDA), is able to quantify 10 RNA copies.µL-1. In 164 clinical oropharyngeal RNA samples, NISDA assay is 100 % specific, and it is 96.77% and 100% sensitive when setting up in the laboratory and hospital, respectively. The NISDA assay does not require RNA reverse-transcription step and is fast (<30 min), affordable, highly robust at room temperature (>1 month), isothermal (42 °C) and user-friendly, making it an excellent assay for broad-based testing.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA Viral/isolamento & purificação , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , COVID-19/virologia , Teste para COVID-19 , Humanos , RNA Viral/genética , Recombinação Genética
7.
Phys Rev E ; 103(5-1): 052218, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34134244

RESUMO

A new basis has been found for the theory of self-organization of transport avalanches and jet zonal flows in L-mode tokamak plasma, the so-called "plasma staircase" [Dif-Pradalier et al., Phys. Rev. E 82, 025401(R) (2010)PLEEE81539-375510.1103/PhysRevE.82.025401]. The jet zonal flows are considered as a wave packet of coupled nonlinear oscillators characterized by a complex time- and wave-number-dependent wave function; in a mean-field approximation this function is argued to obey a discrete nonlinear Schrödinger equation with subquadratic power nonlinearity. It is shown that the subquadratic power leads directly to a white Lévy noise, and to a Lévy fractional Fokker-Planck equation for radial transport of test particles (via wave-particle interactions). In a self-consistent description the avalanches, which are driven by the white Lévy noise, interact with the jet zonal flows, which form a system of semipermeable barriers to radial transport. We argue that the plasma staircase saturates at a state of marginal stability, in whose vicinity the avalanches undergo an ever-pursuing localization-delocalization transition. At the transition point, the event-size distribution of the avalanches is found to be a power law w_{τ}(Δn)∼Δn^{-τ}, with the drop-off exponent τ=(sqrt[17]+1)/2≃2.56. This value is an exact result of the self-consistent model. The edge behavior bears signatures enabling to associate it with the dynamics of a self-organized critical (SOC) state. At the same time the critical exponents, pertaining to this state, are found to be inconsistent with classic models of avalanche transport based on sand piles and their generalizations, suggesting that the coupled avalanche-jet zonal flow system operates on different organizing principles. The results obtained have been validated in a numerical simulation of the plasma staircase using flux-driven gyrokinetic code for L-mode Tore-Supra plasma.

8.
Metabolites ; 11(4)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808080

RESUMO

Medication deprescribing is essential to prevent inappropriate medication use in multimorbid patients. However, experience of deprescribing in Danish Subacute Medical Outpatient Clinics (SMOCs) is limited. The objective of our pilot study was to evaluate the feasibility and sustainability of a collaborative deprescribing intervention by a pharmacist and a physician to multimorbid patients in a SMOC. A randomized controlled pilot study was conducted, with phone follow-up at 30 and 365+ days. A senior pharmacist performed a systematic deprescribing intervention using the Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) criteria, the Danish deprescribing list, and patient interviews. A senior physician received the proposed recommendations and decided which should be implemented. The main outcome was the number of patients having ≥1 medication where deprescribing status was sustained 30 days after inclusion. Out of 76 eligible patients, 72 (95%) were included and 67 (93%) completed the study (57% male; mean age 73 years; mean number of 10 prescribed medications). Nineteen patients (56%) in the intervention group and four (12%) in the control group had ≥1 medication where deprescribing status was sustained 30 days after inclusion (p = 0.015). In total, 37 medications were deprescribed in the intervention group and five in the control group. At 365+ days after inclusion, 97% and 100% of the deprescribed medications were sustained in the intervention and control groups, respectively. The three most frequently deprescribed medication groups were analgesics, cardiovascular, and gastrointestinal medications. In conclusion, a collaborative deprescribing intervention for multimorbid patients was feasible and resulted in sustainable deprescribing of medication in a SMOC.

9.
J Clin Med ; 11(1)2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-35011944

RESUMO

C-reactive protein (CRP) has prognostic value in hospitalized patients with COVID-19; the importance of CRP in pre-hospitalized patients remains to be tested. Methods: Individuals with symptoms of COVID-19 had a SARS-CoV-2 PCR oropharyngeal swab test, and a measurement of CRP was performed at baseline, with an upper reference range of 10 mg/L. After 28 days, information about possible admissions, oxygen treatments, transfers to the ICU, or deaths was obtained from the patient files. Using logistic regression, the prognostic value of the CRP and SARS-CoV-2 test results was evaluated. Results: Among the 1006 patients included, the SARS-CoV-2 PCR test was positive in 59, and the CRP level was elevated (>10 mg/L) in 131. In total, 59 patients were hospitalized, only 3 of whom were SARS-CoV-2 positive, with elevated CRP (n = 2) and normal CRP (n = 1). The probability of being hospitalized with elevated CRP was 4.21 (95%CI 2.38-7.43, p < 0.0001), while the probability of being hospitalized with SARS-CoV-2 positivity alone was 0.85 (95%CI 0.26-2.81, p = 0.79). Conclusions: CRP is not a reliable predictor for the course of SARS-CoV-2 infection in pre-hospitalized patients. CRP, while not a SARS-CoV-2 positive test, had prognostic value in the total population of patients presenting with COVID-19-related symptoms.

10.
Materials (Basel) ; 13(20)2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33065961

RESUMO

Plasma probes are simple and inexpensive diagnostic tools for fast measurements of relevant plasma parameters. While in earlier times being employed mainly in relatively cold laboratory plasmas, plasma probes are now routinely used even in toroidal magnetic fusion experiments, albeit only in the edge region, i.e., the so-called scrape-off layer (SOL), where temperature and density of the plasma are lower. To further avoid overheating and other damages, in medium-size tokamak (MST) probes are inserted only momentarily by probe manipulators, with usually no more than a 0.1 s per insertion during an average MST discharge of a few seconds. However, in such hot and high-density plasmas, their usage is limited due to the strong particle fluxes onto the probes and their casing which can damage the probes by sputtering and heating and by possible chemical reactions between plasma particles and the probe material. In an attempt to make probes more resilient against these detrimental effects, we tested two graphite probe heads (i.e., probe casings with probes inserted) coated with a layer of electrically isolating ultra-nano-crystalline diamond (UNCD) in the edge plasma region of the Experimental Advanced Superconducting Tokamak (EAST) in Hefei, People's Republic of China. The probe heads, equipped with various graphite probe pins, were inserted frequently even into the deep SOL up to a distance of 15 mm inside the last closed flux surface (LCFS) in low- and high-confinement regimes (L-mode and H-mode). Here, we concentrate on results most relevant for the ability to protect the graphite probe casings by UNCD against harmful effects from the plasma. We found that the UNCD coating also prevented almost completely the sputtering of graphite from the probe casings and thereby the subsequent risk of re-deposition on the boron nitride isolations between probe pins and probe casings by a layer of conductive graphite. After numerous insertions into the SOL, first signs of detachment of the UNCD layer were noticed.

11.
Musculoskeletal Care ; 18(4): 510-518, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32686272

RESUMO

OBJECTIVE: To study the association between self-reported physical activity level and overall attitudes and barriers to and facilitators of physical activity in people with axial spondyloarthritis (axSpA), and to compare health status and quality of life (QoL) in people with different levels of physical activity. METHODS: Four hundred forty-five members of the Danish Patient Association for Axial Spondyloarthritis completed an online survey including questions on physical activity, overall attitudes, barriers, and facilitators to physical activity, health, and QoL. Nonparametric tests and logistic regression analyses were performed. RESULTS: The response rate was 46%, median age 56 years (range 22-85), and 54% were men. In all, 23% reported low physical activity (physical activity ≥30 min on a moderate intensity level ≤1 day/week), 36% were moderately physically active (2-3 days/week), and 41% reported high physical activity (≥4 days/week). In a multivariate model, high physical activity was associated with a positive overall attitude ("physical activity is ok," OR 5.44, 95%CI [1.24, 23.87], and "I like physical activity," OR 14.22, 95%CI [3.34, 60.61]), and higher disagreement with barriers to physical activity, OR 1.12, 95%CI [1.07, 1.17]). People with moderate or high physical activity levels reported better self-perceived health and QoL, compared with those with low physical activity level (p ≤ 0.003). CONCLUSION: To support changes in physical activity level in people with axSpA, health professionals need to discuss attitudes and barriers to physical activity with their clients. Barriers seem to be of greater significance than facilitators of any kind.


Assuntos
Espondilartrite , Espondilite Anquilosante , Adulto , Idoso , Idoso de 80 Anos ou mais , Atitude , Estudos Transversais , Exercício Físico , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Adulto Jovem
12.
Phys Rev E ; 98(2-1): 022208, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30253554

RESUMO

We formulate the problem of confined Lévy flight on a comb. The comb represents a sawtoothlike potential field V(x), with the asymmetric teeth favoring net transport in a preferred direction. The shape effect is modeled as a power-law dependence V(x)∝|Δx|^{n} within the sawtooth period, followed by an abrupt drop-off to zero, after which the initial power-law dependence is reset. It is found that the Lévy flights will be confined in the sense of generalized central limit theorem if (i) the spacing between the teeth is sufficiently broad, and (ii) n>4-µ, where µ is the fractal dimension of the flights. In particular, for the Cauchy flights (µ=1), n>3. The study is motivated by recent observations of localization-delocalization of transport avalanches in banded flows in the Tore Supra tokamak and is intended to devise a theory basis to explain the observed phenomenology.

14.
Opt Express ; 21(26): 32393-9, 2013 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-24514832

RESUMO

We experimentally and numerically investigated the characteristics of 128 Gb/s dual polarization - quadrature phase shift keying signals received with two types of nonlinear equalizers (NLEs) followed by soft-decision (SD) low-density parity-check (LDPC) forward error correction (FEC). Successful co-operation among SD-FEC and NLEs over various nonlinear transmissions were demonstrated by optimization of parameters for NLEs.

15.
J Rehabil Med ; 44(11): 901-12, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23026978

RESUMO

OBJECTIVES: To systematically investigate current scientific evidence about the effectiveness of multidisciplinary team rehabilitation for different health problems. DATA SOURCES: A comprehensive literature search was conducted in Cochrane, Medline, DARE, Embase, and Cinahl databases, and research from existing systematic reviews was critically appraised and summarized. STUDY SELECTION: Using the search terms "rehabilitation", "multidisciplinary teams" or "team care", references were identified for existing studies published after 2000 that examined multidisciplinary rehabilitation team care for adults, without restrictions in terms of study population or outcomes. The most recent reviews examining a study population were selected. DATA EXTRACTION: Two reviewers independently extracted information about study populations, sample sizes, study designs, rehabilitation settings, the team, interventions, and findings. DATA SYNTHESIS: A total of 14 reviews were included to summarize the findings of 12 different study populations. Evidence was found to support improved functioning following multidisciplinary rehabilitation team care for 10 of 12 different study population: elderly people, elderly people with hip fracture, homeless people with mental illness, adults with multiple sclerosis, stroke, acquired brain injury, chronic arthropathy, chronic pain, low back pain, and fibromyalgia. Whereas evidence was not found for adults with amyetrophic lateral schlerosis, and neck and shoulder pain. CONCLUSION: Although these studies included heterogeneous patient groups the overall conclusion was that multidisciplinary rehabilitation team care effectively improves rehabilitation intervention. However, further research in this area is needed.


Assuntos
Encefalopatias/reabilitação , Fraturas do Quadril/reabilitação , Transtornos Mentais/reabilitação , Esclerose Múltipla/reabilitação , Doenças Musculoesqueléticas/reabilitação , Dor/reabilitação , Equipe de Assistência ao Paciente , Terapia Combinada , Humanos
16.
Dan Med J ; 59(12): A4554, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23290290

RESUMO

INTRODUCTION: Clinical practice does not reflect current clinical guidelines recommending an early multimodal non-surgical treatment for knee and hip osteoarthritis (OA). The purpose of this study was to examine the feasibility of such an initiative (Good Life with osteoArthritis in Denmark (GLA:D) in persons with mild to moderate knee and/or hip OA-related pain. MATERIAL AND METHODS: This was a pilot study with a 36-patient cohort and three-month follow-up. The treatment consisted of two 1.5-hour sessions of patient education and six weeks of individualized supervised neuromuscular exercise according to the previously published NEuroMuscular Exercise programme. The primary outcome was pain on a visual analogue scale (0-100). Secondary outcomes were Euro-Quality-of-Life - 5 Dimensional form (EQ-5D), Arthritis Self-Efficacy Scale (ASES), 30-second chair stand test, timed 20-meter walk and body mass index. Furthermore, compliance was registered. RESULTS: Thirty-four (94%) participants completed the follow-up. There were significant improvements (p < 0.05) in the primary outcome pain (-16 mm), in time in the 20-meter walk test (-0.7 s), in EQ-5D (0.053), in ASES (7.3) and in the number of complete chair stands (1.4). Compliance was high in relation to both patient education and exercise. CONCLUSION: The pilot study demonstrated that the intervention is feasible and that it is possible to implement GLA:D in clinical care. Introducing GLA:D nationwide could improve the adherence to clinical guidelines and the quality of the treatment of knee and hip OA.


Assuntos
Terapia por Exercício/métodos , Osteoartrite do Quadril/terapia , Osteoartrite do Joelho/terapia , Educação de Pacientes como Assunto/métodos , Amplitude de Movimento Articular/fisiologia , Idoso , Artralgia/diagnóstico , Artralgia/terapia , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Quadril/diagnóstico , Osteoartrite do Joelho/diagnóstico , Medição da Dor , Cooperação do Paciente/estatística & dados numéricos , Projetos Piloto , Psicoterapia de Grupo , Recuperação de Função Fisiológica , Medição de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
17.
Phys Med Biol ; 56(6): 1853-63, 2011 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-21364259

RESUMO

RapidArc® has become the treatment of choice for an increasing number of treatment sites in many clinics. The extensive use of multiple subfields in RapidArc® treatments presents unique challenges, especially for small targets treated in few fractions. In this work, very small static fields and subsequently RapidArc® and conventional plans for two targets (0.4 and 9.9 cm(3)) were investigated. Doses from static fields 1-4 MLC leaves (0.25-1.00 cm) wide, and larger fields with 1-4 MLC leaves closed in their centres, were measured using the portal dosimeter-based QA system EPIQA (v 1.3) and gafchromic film. RapidArc and conventional plans for two tumours were then measured using EPIQA, gafchromic EBT2 film and the phantom-based QA system Delta4. Eclipse 8.6 and 8.9, grid spacings of 1.25 and 2.50 mm and a Varian HD linac were used. For static fields one MLC leaf wide, the dose was underestimated by Eclipse by as much as 53% (v 8.6, 2.5 mm grid). Eclipse underestimated the dose downstream from a few MLC leaves closed in the centre of a large MLC field by as much as 30%. Eclipse consistently overestimated the width of the penumbra by about 100%. For the conventional plans, there was good agreement between the calculated and measured dose for the 9.9 cm(3) PTV, but a 10% underdose was observed for the 0.4 cm(3) PTV. For the RapidArc® plans, the measured dose for the 9.9 cm(3) PTV was in good agreement with the calculated one. However, for the 0.4 cm(3) PTV about 10% overdosing was detected (Eclipse v 8.6, 2.5 mm grid spacing). EPIQA data indicated that the measured dose profiles were overmodulated compared to the calculated one. The use of small subfields, typically a few MLC leaves wide, or larger fields with one or a few MLC leaves closed in its centre can result in significant errors in the dose calculation. The detector systems used vary in their ability to detect the discrepancies. Using a smaller grid size and newer version of Eclipse reduces the discrepancies observed in this work but does not eliminate them.


Assuntos
Neoplasias/radioterapia , Neoplasias/cirurgia , Radiocirurgia/métodos , Radioterapia Assistida por Computador/métodos , Algoritmos , Humanos , Neoplasias/patologia , Imagens de Fantasmas , Doses de Radiação , Radiocirurgia/instrumentação , Dosagem Radioterapêutica
18.
Ugeskr Laeger ; 172(38): 2604-7, 2010 Sep 20.
Artigo em Dinamarquês | MEDLINE | ID: mdl-20920404

RESUMO

Intrastriatal, foetal neural transplants can ameliorate symptoms in patients with Parkinson's and Huntington's disease, although not stop the primary cell-loss. Several issues must, however, be addressed before general or extended clinical use of cell therapy in neurodegenerative diseases can become a reality. Improvements include standardized and safe master cell-lines derived from human embryonic stem cells, induced pluripotent stem cells and neural stem cells. Cells from these sources are expected to become available for cell replacement therapies or therapeutic production of trophic, anti-inflammatory and restorative factors within a few years.


Assuntos
Doenças Neurodegenerativas/terapia , Transplante de Células-Tronco , Animais , Reprogramação Celular , Células-Tronco Embrionárias/fisiologia , Células-Tronco Embrionárias/transplante , Transplante de Tecido Fetal , Humanos , Doença de Huntington/terapia , Doença de Parkinson/terapia , Células-Tronco Pluripotentes/fisiologia , Células-Tronco Pluripotentes/transplante , Transplante de Células-Tronco/métodos
19.
Opt Express ; 17(16): 13860-8, 2009 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-19654792

RESUMO

Cross-phase modulation (XPM) has been considered as one of the ultimate obstacles for optical coherent dense wavelength division multiplexing (DWDM) systems. In order to facilitate the XPM analysis, a simplified model was proposed. The model reduced the distributed XPM phenomena to a lumped phase modulation. The XPM phase noise was generated by a linear system which was determined by the DWDM system parameters and whose inputs were undistorted pump channel intensity waveforms. The model limitations induced by the lumped phase modulation and undistorted pumps approximations were intensively discussed and verified. The simplified model showed a good agreement with simulations and experiments for a typical hybrid optical coherent system. Various XPM phenomena were explained by the proposed model.


Assuntos
Desenho Assistido por Computador , Lasers , Modelos Teóricos , Processamento de Sinais Assistido por Computador/instrumentação , Telecomunicações/instrumentação , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Luz , Dinâmica não Linear , Espalhamento de Radiação
20.
Joint Bone Spine ; 75(6): 708-13, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19028434

RESUMO

OBJECTIVES: Both exercises and manipulation are recommended as basic therapy in back diseases, while a possible synergistic effect of these treatments have not been clarified. This study was conducted to test a possible further effect of manipulation as adjunct to extension exercises for unspecific LBP. METHODS: 72 patients with chronic LBP (mean 12 months) were examined by a specialist in manual medicine, who detected localized binding between the lumbar segments. All patients were instructed in extension exercises, while randomized to either pretreatment with specific manipulation or control. The patients were blinded to the manipulation, which was performed at the end of the manual examination, and repeated after two and four weeks. The manipulator only knew the group of the particular patient just before manipulation by the end of the examination. The primary end point was pain, measured by a visual analogue scale. RESULTS: Pain in both back and leg decreased without differences between groups. Segmental binding of the low-back was associated with persisting clinical symptoms at four weeks. CONCLUSION: No additional effect was demonstrated of manipulation, when extension exercises were used as basic therapy.


Assuntos
Terapia por Exercício , Dor Lombar/terapia , Manipulações Musculoesqueléticas , Adulto , Idoso , Doença Crônica , Método Duplo-Cego , Feminino , Humanos , Perna (Membro)/fisiopatologia , Dor Lombar/fisiopatologia , Masculino , Pessoa de Meia-Idade , Atividade Motora , Medição da Dor , Resultado do Tratamento
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