O efeito da descontinuação dos corticóides inalados em doentes com Doença Pulmonar Obstrutiva Crónica — O estudo COPE

RESUMO: Os autores desenharam um estudo duplamente cego para investigar o efeito da descontinuação do propionato de fluticasona (PF) nas exacerbações e qualidade de vida em doentes com DPOC (estudo COPE).Durante 4 meses, 244 doentes com DPOC foram medicados com propionato de fluticasona (1000 (g /dia).A selecção dos doentes baseou se em critérios clínicos e funcionais e idade compreendida entre os 40 e os 75 anos. Após este período de tempo, 123 doentes mantiveram o tratamento com PF e 121 doentes receberam placebo durante 6 meses. As visitas de controlo ocorreram aos 3 e 6 meses, tendo os doentes sido avaliados do ponto de vista funcional e clínico. Os critérios analisados no estudo foram o número, gravidade e intervalo de tempo entre as exacerbações, a qualidade de vida (questionário respiratório de St Georgeâs), parâmetros funcionais respiratórios (espirometria) e tolerância ao esforço (prova de 6 minutos de marcha standardizada).Na análise dos resultados, os autores demonstraram que no grupo medicado com PF, 47% dos doentes sofreram pelo menos uma agudização, em contraste dos 57 % do grupo placebo. No grupo placebo, 21 % dos doentes apresentaram exacerbações recorrentes e rápidas, ao contrário dos 6% de doentes medicados com PF. Em termos de qualidade de vida, uma diferença significativa ocorreu também entre os 2 grupos, a nível do score total, actividade e sintomas.Não se verificaram diferenças na prova de marcha entre os 2 grupos avaliados. O estudo funcional mostrou uma diferença significativa de 38 ml de VEMS pós-broncodilatação, a favor do grupo medicado com FP.Este estudo indica que a descontinuação de PF em doentes com DPOC está associada a um mais rápido início e recorrência de agudização, bem como uma deterioração maior da qualidade de vida. COMENTÃRIO: Estima-se que a DPOC constitua a 5.ª doença mais frequente e a 4.ª causa de morte a nível mundial.Não existindo cura para esta doença, a terapêutica assenta fundamentalmente na broncodilatação e na evicção tabágica.Sabe se que apesar de a DPOC ser uma doença inflamatória crónica das vias aéreas, os corti cóides inalados (CI) não modificam o declínio mais acelerado do VEMS constatado na DPOC.Múltiplos estudos foram efectuados tendo como um dos objectivos determinar a validade da utilização de CI na DPOC, dos quais se salienta:O estudo EUROSCOP revela eficácia reduzida e transitória do budesonido; o estudo ISOLDE mostrou uma pequena redução no declínio do VEMS, um menor número de exacerbações e score sintomático, em doentes com DPOC grave tratados com fluticasona e o estudo COPENHAGEN não demonstrou qualquer beneficio do budesonido na DPOC ligeira e moderada.O projecto GOLD considera os CI como fármacos de 2.ª linha no tratamento da DPOC, mas refere também uma melhoria sintomática, uma redução no número e gravidade das exacerbações e melhoria da qualidade de vida.Este estudo vem exactamente reforçar o efeito benéfico dos CI em doentes com DPOC a nível da qualidade de vida e frequência e gravidade das agudizações, assim como o agravamento destes parâmetros após a suspensão dos CI. Palavras-chave: Corticóides inalados, DPOC, Qualidade de vida, Exacerbaçã

Pressure dependence of Raman modes in double wall carbon nanotubes filled with α-Fe.

The preparation of highly anisotropic one-dimensional (1D) structures confined into carbon nanotubes (CNTs) in general is a key objective in CNTs research. In this work, the capillary effect was used to fill double wall carbon nanotubes with iron. The samples are characterized by Mössbauer and Raman spectroscopy, transmission electron microscopy, scanning area electron diffraction, and magnetization. In order to investigate their structural stability and compare it with that of single wall carbon nanotubes (SWNTs), elucidating the differences induced by the inner-outer tube interaction, unpolarized Raman spectra of tangential modes of double wall carbon nanotubes (DWNTs) filled with 1D nanocrystallin α-Fe excited with 514 nm were studied at room temperature and elevated pressure. Up to 16 GPa we find a pressure coefficient for the internal tube of 4.3 cm−1 GPa−1 and for the external tube of 5.5 cm−1 GPa−1. In addition, the tangential band of the external and internal tubes broadens and decreases in amplitude. All findings lead to the conclusion that the outer tube acts as a protection shield for the inner tubes (at least up 16 GPa). Structural phase transitions were not observed in this range of pressure

Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands

Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916–2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce wetland habitat availability for many species

Solving the Klein-Gordon equation using Fourier spectral methods: A benchmark test for computer performance

The cubic Klein-Gordon equation is a simple but non-trivial partial differential equation whose numerical solution has the main building blocks required for the solution of many other partial differential equations. In this study, the library 2DECOMP&FFT is used in a Fourier spectral scheme to solve the Klein-Gordon equation and strong scaling of the code is examined on thirteen different machines for a problem size of 512^3. The results are useful in assessing likely performance of other parallel fast Fourier transform based programs for solving partial differential equations. The problem is chosen to be large enough to solve on a workstation, yet also of interest to solve quickly on a supercomputer, in particular for parametric studies. Unlike other high performance computing benchmarks, for this problem size, the time to solution will not be improved by simply building a bigger supercomputer.Comment: 10 page

Leisure constraints for adolescents in Cape Town, South Africa: a qualitative study

This study identified leisure constraints, constraints negotiation strategies, and their relative frequencies among 114 high school students from one under-resourced area of South Africa. Through focus group discussions, participants identified intrapersonal, interpersonal, structural, and sociocultural constraints to leisure, suggesting some degree of universality in this previously documented typology. Intrapersonal constraints were mentioned most often. Whereas participants readily identified ways to overcome interpersonal and structural constraints, strategies for overcoming intrapersonal and sociocultural constraints were not mentioned frequently, suggesting a potential need to help adolescents identify and employ these types of strategies.Web of Scienc

Structural Modification in Carbon Nanotubes by Boron Incorporation

We have synthesized boron-incorporated carbon nanotubes (CNTs) by decomposition of ferrocene and xylene in a thermal chemical vapor deposition set up using boric acid as the boron source. Scanning and transmission electron microscopy studies of the synthesized CNT samples showed that there was deterioration in crystallinity and improvement in alignment of the CNTs as the boron content in precursor solution increased from 0% to 15%. Raman analysis of these samples showed a shift of ~7 cm−1in wave number to higher side and broadening of the G band with increasing boron concentration along with an increase in intensity of the G band. Furthermore, there was an increase in the intensity of the D band along with a decrease in its wave number position with increase in boron content. We speculate that these structural modifications in the morphology and microstructure of CNTs might be due to the charge transfer from boron to the graphite matrix, resulting in shortening of the carbon–carbon bonds

E-Voting in an ubicomp world: trust, privacy, and social implications

The advances made in technology have unchained the user from the desktop into interactions where access is anywhere, anytime. In addition, the introduction of ubiquitous computing (ubicomp) will see further changes in how we interact with technology and also socially. Ubicomp evokes a near future in which humans will be surrounded by “always-on,” unobtrusive, interconnected intelligent objects where information is exchanged seamlessly. This seamless exchange of information has vast social implications, in particular the protection and management of personal information. This research project investigates the concepts of trust and privacy issues specifically related to the exchange of e-voting information when using a ubicomp type system

Comparison of serious inhaler technique errors made by device-naïve patients using three different dry powder inhalers: a randomised, crossover, open-label study

Background: Serious inhaler technique errors can impair drug delivery to the lungs. This randomised, crossover, open-label study evaluated the proportion of patients making predefined serious errors with Pulmojet compared with Diskus and Turbohaler dry powder inhalers. Methods: Patients ≥18 years old with asthma and/or COPD who were current users of an inhaler but naïve to the study devices were assigned to inhaler technique assessment on Pulmojet and either Diskus or Turbohaler in a randomised order. Patients inhaled through empty devices after reading the patient information leaflet. If serious errors potentially affecting dose delivery were recorded, they repeated the inhalations after watching a training video. Inhaler technique was assessed by a trained nurse observer and an electronic inhalation profile recorder. Results: Baseline patient characteristics were similar between randomisation arms for the Pulmojet-Diskus (n = 277) and Pulmojet-Turbohaler (n = 144) comparisons. Non-inferiority in the proportions of patients recording no nurse-observed serious errors was demonstrated for both Pulmojet versus Diskus, and Pulmojet versus Turbohaler; therefore, superiority was tested. Patients were significantly less likely to make ≥1 nurse-observed serious errors using Pulmojet compared with Diskus (odds ratio, 0.31; 95 % CI, 0.19–0.51) or Pulmojet compared with Turbohaler (0.23; 0.12–0.44) after reading the patient information leaflet with additional video instruction, if required. Conclusions These results suggest Pulmojet is easier to learn to use correctly than the Turbohaler or Diskus for current inhaler users switching to a new dry powder inhaler

The association between preoperative body composition and aerobic fitness in patients scheduled for colorectal surgery

AIM: Although cardiopulmonary exercise testing (CPET) is considered the gold standard, a preoperative abdominal CT scan might also provide information concerning preoperative aerobic fitness for risk assessment. This study aimed to investigate the association between preoperative CT‐scan‐derived body composition variables and preoperative CPET variables of aerobic fitness in colorectal surgery. METHOD: In this retrospective cohort study, CT images at level L3 were analysed for skeletal muscle mass, skeletal muscle radiation attenuation, visceral adipose tissue (VAT) mass and subcutaneous adipose tissue mass. Regression analyses were performed to investigate the relation between CT‐scan‐derived body composition variables, CPET‐derived aerobic fitness and other preoperative patient‐related variables. Logistic regression analysis was performed to predict a preoperative anaerobic threshold (AT) ≤ 11.1 ml/kg/min as cut‐off for having a high risk for postoperative complications. RESULTS: Data from 78 patients (45 men; mean [SD] age 74.5 [6.4 years]) were analysed. A correlation coefficient of 0.55 was observed between absolute AT and skeletal muscle mass index. Absolute AT (R (2) of 51.1%) was lower in patients with a lower skeletal muscle mass index, together with higher age, lower body mass and higher American Society of Anesthesiologists (ASA) score. Higher ASA score (odds ratio 5.64; P = 0.033) and higher VAT mass (odds ratio 1.02; P = 0.036) were associated with an increased risk of an AT ≤ 11.1 ml/kg/min. CONCLUSION: Body composition variables from the preoperative CT scan were moderately associated with preoperative CPET‐derived aerobic fitness. Higher ASA score and higher VAT mass were associated with an increased risk of an AT ≤ 11.1 ml/kg/min