64 research outputs found
Effective slip boundary conditions for arbitrary one-dimensional surfaces
In many applications it is advantageous to construct effective slip boundary
conditions, which could fully characterize flow over patterned surfaces. Here
we focus on laminar shear flows over smooth anisotropic surfaces with arbitrary
scalar slip , varying in only one direction. We derive general
expressions for eigenvalues of the effective slip-length tensor, and show that
the transverse component is equal to a half of the longitudinal one with twice
larger local slip, . A remarkable corollary of this relation is that the
flow along any direction of the 1D surface can be easily determined, once the
longitudinal component of the effective slip tensor is found from the known
spatially nonuniform scalar slip.Comment: 10 pages, 2 figures, submitted to J. Fluid Mec
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Evaluating methane inventories by isotopic analysis in the London region
A thorough understanding of methane sources is necessary to accomplish methane reduction targets. Urban environments, where a large variety of methane sources coexist, are one of the most complex areas to investigate. Methane sources are characterised by specific δ13C-CH4 signatures, so high precision stable isotope analysis of atmospheric methane can be used to give a better understanding of urban sources and their partition in a source mix. Diurnal measurements of methane and carbon dioxide mole fraction, and isotopic values at King’s College London, enabled assessment of the isotopic signal of the source mix in central London. Surveys with a mobile measurement system in the London region were also carried out for detection of methane plumes at near ground level, in order to evaluate the spatial allocation of sources suggested by the inventories. The measured isotopic signal in central London (−45.7 ±0.5‰) was more than 2‰ higher than the isotopic value calculated using emission inventories and updated δ13C-CH4 signatures. Besides, during the mobile surveys, many gas leaks were identified that are not included in the inventories. This suggests that a revision of the source distribution given by the emission inventories is needed
Ibrutinib in the Treatment of Refractory Chronic Lymphocytic Leukemia
Background & Aims. This paper presents the results of the observational study of ibrutinib in patients with chronic lymphocytic leukemia (CLL), conducted in SP Botkin Municipal Clinical Hospital. The main objective was the analysis of complications of ibrutinib and identification of factors, influencing the dosage regimen; the secondary objective was the estimation of the total response to treatment, event-free and overall survival.
Materials & Methods. The study included 96 patients with CLL with indications for ibrutinib therapy. The median age was 64,9 years (range 32–91 years), the study population consisted of 69 (72 %) men and 27 (28 %) women. The condition of 25 (26 %) patients according to the ECOG scale was of > 3 points. The disease of stage C were diagnosed in 36 (37 %) patients . Deletion of 17p/TP53 mutations were detected in 29 (33 %) of 87 patients. Seventy patients had refractory CLL. The median of the number of the lines of the previous therapy was 3 (range 1–9). Adverse events were assessed in accordance with the CTCAE criteria, version 4.0; the bleeding severity was evaluated using ITP-specific bleeding score; hematological complications were classified according to the recommendations of IWCLL-2008.
Results. Ibrutinib was administered at a dosage of 420 mg per day daily until progression or intolerable toxicity. The median duration of ibrutinib therapy was 10.3 months. Ibrutinib was shown to have moderate toxicity, mostly of grade I or II. The bleeding was the most frequent complication. Of the hematological complications, thrombocytopenia was the most common (35 %); neutropenia grade III) developed in 26 % of patients. The treatment response was assessed in 92 patients. The overall response to treatment was 89 %. Complete remission, partial remission and partial remission with lymphocytosis were achieved in 4 (4 %), 57 (62 %), and 21 (23 %) patients, respectively. The event-free survival and overall survival by the month 10 was 90 % and 91 %, respectively. For this observation period, ECOG status and the number of the lines of therapy prior to ibrutinib had the prognostic value.
Conclusion. Ibrutinib was shown to have high efficiency in relapsed/refractory forms of CLL. The nature of the ibrutinib toxicity is fundamentally different from that of the conventional chemotherapy. The frequency of ibrutinib therapy complications and patients’ non-compliance depends on the intensity of the previous treatment of CLL. Despite a short observation period, it can be concluded that ibrutinib had the greatest impact on the patient’s quality of life when administered for the first relapse. The low toxicity of ibrutinib is likely to allow the combination with other antitumor agents
Integrins as therapeutic targets: lessons and opportunities.
The integrins are a large family of cell adhesion molecules that are essential for the regulation of cell growth and function. The identification of key roles for integrins in a diverse range of diseases, including cancer, infection, thrombosis and autoimmune disorders, has revealed their substantial potential as therapeutic targets. However, so far, pharmacological inhibitors for only three integrins have received marketing approval. This article discusses the structure and function of integrins, their roles in disease and the chequered history of the approved integrin antagonists. Recent advances in the understanding of integrin function, ligand interaction and signalling pathways suggest novel strategies for inhibiting integrin function that could help harness their full potential as therapeutic targets
Electrocatalytic Hydrogen Evolution in Acidic Water with Molecular Cobalt Tetraazamacrocycles
Finding of the macrophagous deep-sea ascidian Dicopia antirrhinum
This study reports the in situ observations of a deep-sea ascidian, Dicopia antirrhinum (family Octacnemidae), on the deep seabed off the Aeolian Islands (Tyrrhenian Sea), between 569 and 813 m depth. These observations represent the first record of the species in Italian waters and the second observation in vivo to date. Peculiar macroscopic features are described here and the main differences from other species of the family Octacnemidae are highlighted, in order to allow the future identification of D. antirrhinum through visual technologies such as remotely operated vehicles. A total of 29 specimens were observed, with a maximum density of 0.012 specimens/m2. The global geographic and bathymetric distribution of D. antirrhinum known so far is also updated and discussed
Respiratory, cardiac, EEG, BOLD signals and functional connectivity over multiple microsleep episodes
Falling asleep is common in fMRI studies. By using long eyelid closures to detect microsleep onset, we showed that the onset and termination of short sleep episodes invokes a systematic sequence of BOLD signal changes that are large, widespread, and consistent across different microsleep durations. The signal changes are intimately intertwined with shifts in respiration and heart rate, indicating that autonomic contributions are integral to the brain physiology evaluated using fMRI and cannot be simply treated as nuisance signals. Additionally, resting state functional connectivity (RSFC) was altered in accord with the frequency of falling asleep and in a manner that global signal regression does not eliminate. Our findings point to the need to develop a consensus among neuroscientists using fMRI on how to deal with microsleep intrusions. Significance Statement: Sleep, breathing and cardiac action are influenced by common brainstem nuclei. We show that falling asleep and awakening are associated with a sequence of BOLD signal changes that are large, widespread and consistent across varied durations of sleep onset and awakening. These signal changes follow closely those associated with deceleration and acceleration of respiration and heart rate, calling into question the separation of the latter signals as ‘noise’ when the frequency of falling asleep, which is commonplace in RSFC studies, correlates with the extent of RSFC perturbation. Autonomic and central nervous system contributions to BOLD signal have to be jointly considered when interpreting fMRI and RSFC studies
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