Making a splash with water repellency

A 'splash' is usually heard when a solid body enters water at large velocity. This phenomena originates from the formation of an air cavity resulting from the complex transient dynamics of the free interface during the impact. The classical picture of impacts on free surfaces relies solely on fluid inertia, arguing that surface properties and viscous effects are negligible at sufficiently large velocities. In strong contrast to this large-scale hydrodynamic viewpoint, we demonstrate in this study that the wettability of the impacting body is a key factor in determining the degree of splashing. This unexpected result is illustrated in Fig.1: a large cavity is evident for an impacting hydrophobic sphere (1.b), contrasting with the hydrophilic sphere's impact under the very same conditions (1.a). This unforeseen fact is furthermore embodied in the dependence of the threshold velocity for air entrainment on the contact angle of the impacting body, as well as on the ratio between the surface tension and fluid viscosity, thereby defining a critical capillary velocity. As a paradigm, we show that superhydrophobic impacters make a big 'splash' for any impact velocity. This novel understanding provides a new perspective for impacts on free surfaces, and reveals that modifications of the detailed nature of the surface -- involving physico-chemical aspects at the nanometric scales -- provide an efficient and versatile strategy for controlling the water entry of solid bodies at high velocity.Comment: accepted for publication in Nature Physic

Combined sterno-clavicular approach as an alternative technique in hybrid exclusion of aortic arch aneurysm

<p>Abstract</p> <p>Background</p> <p>We describe a modified access technique for the proximal (open) part of single stage hybrid exclusion of aneurysm of the aortic arch.</p> <p>Case presentation</p> <p>3 patients had a bifurcated Dacron graft for the innominate and left subclavian arteries and an additional end-to-side anastomosis of the left common carotid artery on the limb to the left subclavian artery. With our modification, access to the left subclavian artery is by left subclavicular incision and creation of an anterior tunnel via the left thoracic outlet from the origin of the left subclavian artery along its anatomical course to the subclavicular plane.</p> <p>Discussion</p> <p>Advantages and disadvantages of this technique in relation to anatomy and pathology.</p

Occurrence of delirium is severely underestimated in the ICU during daily care

Delirium is associated with prolonged intensive care unit (ICU) stay and higher mortality. Therefore, the recognition of delirium is important. We investigated whether intensivists and ICU nurses could clinically identify the presence of delirium in ICU patients during daily care. All ICU patients in a 3-month period who stayed for more than 48 h were screened daily for delirium by attending intensivists and ICU nurses. Patients were screened independently for delirium by a trained group of ICU nurses who were not involved in the daily care of the patients under study. The Confusion Assessment Method for the ICU (CAM-ICU) was used as a validated screening instrument for delirium. Values are expressed as median and interquartile range (IQR; P25-P75). During the study period, 46 patients (30 male, 16 female), median age 73 years (IQR = 64-80), with an ICU stay of 6 days (range 4-11) were evaluated. CAM-ICU scores were obtained during 425 patient days. Considering the CAM-ICU as the reference standard, delirium occurred in 50% of the patients with a duration of 3 days (range 1-9). Days with delirium were poorly recognized by doctors (sensitivity 28.0%; specificity 100%) and ICU nurses (sensitivity 34.8%; specificity 98.3%). Recognition did not differ between hypoactive or active status of the patients involved. Delirium is severely under recognized in the ICU by intensivists and ICU nurses in daily care. More attention should be paid to the implementation of a validated delirium-screening instrument during daily ICU car

Shape invariant potential formalism for photon-added coherent state construction

An algebro-operator approach, called shape invariant potential method, of constructing generalized coherent states for photon-added particle system is presented. Illustration is given on Poschl-Teller potential

Drug-mediated inhibition of Fli-1 for the treatment of leukemia

The Ets transcription factor, Fli-1 is activated in murine erythroleukemia and overexpressed in various human malignancies including Ewing's sarcoma, induced by the oncogenic fusion protein EWS/Fli-1. Recent studies by our group and others have demonstrated that Fli-1 plays a key role in tumorigenesis, and disrupting its oncogenic function may serve as a potential treatment option for malignancies associated with its overexpression. Herein, we describe the discovery of 30 anti-Fli-1 compounds, characterized into six functional groups. Treatment of murine and human leukemic cell lines with select compounds inhibits Fli-1 protein or mRNA expression, resulting in proliferation arrest and apoptosis. This anti-cancer effect was mediated, at least in part through direct inhibition of Fli-1 function, as anti-Fli-1 drug treatment inhibited Fli-1 DNA binding to target genes, such as SHIP-1 and gata-1, governing hematopoietic differentiation and proliferation. Furthermore, treatment with select Fli-1 inhibitors revealed a positive relationship between the loss of DNA-binding activity and Fli-1 phosphorylation. Accordingly, anti-Fli-1 drug treatment significantly inhibited leukemogenesis in a murine erythroleukemia model overexpressing Fli-1. This study demonstrates the ability of this drug-screening strategy to isolate effective anti-Fli-1 inhibitors and highlights their potential use for the treatment of malignancies overexpressing this oncogene

CCR2 and CXCR3 agonistic chemokines are differently expressed and regulated in human alveolar epithelial cells type II

The attraction of leukocytes from circulation to inflamed lungs depends on the activation of both the leukocytes and the resident cells within the lung. In this study we determined gene expression and secretion patterns for monocyte chemoattractant protein-1 (MCP-1/CCL2) and T-cell specific CXCR3 agonistic chemokines (Mig/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11) in TNF-α-, IFN-γ-, and IL-1β-stimulated human alveolar epithelial cells type II (AEC-II). AEC-II constitutively expressed high level of CCL2 mRNA in vitro and in situ , and released CCL2 protein in vitro . Treatment of AEC-II with proinflammatory cytokines up-regulated both CCL2 mRNA expression and release of immunoreactive CCL2, whereas IFN-γ had no effect on CCL2 release. In contrast, CXCR3 agonistic chemokines were not detected in freshly isolated AEC-II or in non-stimulated epithelial like cell line A549. IFN-γ, alone or in combination with IL-1β and TNF-α resulted in an increase in CXCL10, CXCL11, and CXCL9 mRNA expression and generation of CXCL10 protein by AEC-II or A549 cells. CXCL10 gene expression and secretion were induced in dose-dependent manner after cytokine-stimulation of AEC-II with an order of potency IFN-γ>>IL-1β ≥ TNF-α. Additionally, we localized the CCL2 and CXCL10 mRNAs in human lung tissue explants by in situ hybridization, and demonstrated the selective effects of cytokines and dexamethasone on CCL2 and CXCL10 expression. These data suggest that the regulation of the CCL2 and CXCL10 expression exhibit significant differences in their mechanisms, and also demonstrate that the alveolar epithelium contributes to the cytokine milieu of the lung, with the ability to respond to locally generated cytokines and to produce potent mediators of the local inflammatory response

Antibacterial activity of traditional medicinal plants used by Haudenosaunee peoples of New York State

<p>Abstract</p> <p>Background</p> <p>The evolution and spread of antibiotic resistance, as well as the evolution of new strains of disease causing agents, is of great concern to the global health community. Our ability to effectively treat disease is dependent on the development of new pharmaceuticals, and one potential source of novel drugs is traditional medicine. This study explores the antibacterial properties of plants used in Haudenosaunee traditional medicine. We tested the hypothesis that extracts from Haudenosaunee medicinal plants used to treat symptoms often caused by bacterial infection would show antibacterial properties in laboratory assays, and that these extracts would be more effective against moderately virulent bacteria than less virulent bacteria.</p> <p>Methods</p> <p>After identification and harvesting, a total of 57 different aqueous extractions were made from 15 plant species. Nine plant species were used in Haudenosaunee medicines and six plant species, of which three are native to the region and three are introduced, were not used in traditional medicine. Antibacterial activity against mostly avirulent (<it>Escherichia coli, Streptococcus lactis</it>) and moderately virulent (<it>Salmonella typhimurium, Staphylococcus aureus</it>) microbes was inferred through replicate disc diffusion assays; and observed and statistically predicted MIC values were determined through replicate serial dilution assays.</p> <p>Results</p> <p>Although there was not complete concordance between the traditional use of Haudenosaunee medicinal plants and antibacterial activity, our data support the hypothesis that the selection and use of these plants to treat disease was not random. In particular, four plant species exhibited antimicrobial properties as expected (<it>Achillea millefolium, Ipomoea pandurata, Hieracium pilosella</it>, and <it>Solidago canadensis</it>), with particularly strong effectiveness against <it>S. typhimurium</it>. In addition, extractions from two of the introduced species (<it>Hesperis matronalis </it>and <it>Rosa multiflora</it>) were effective against this pathogen.</p> <p>Conclusions</p> <p>Our data suggest that further screening of plants used in traditional Haudenosaunee medicine is warranted, and we put forward several species for further investigation of activity against <it>S. typhimurium </it>(<it>A. millefolium, H. matronalis, I. pandurata, H. pilosella, R. multiflora, S. canadensis</it>).</p

Gain-of-Function R225W Mutation in Human AMPKγ3 Causing Increased Glycogen and Decreased Triglyceride in Skeletal Muscle

BACKGROUND: AMP-activated protein kinase (AMPK) is a heterotrimeric enzyme that is evolutionarily conserved from yeast to mammals and functions to maintain cellular and whole body energy homeostasis. Studies in experimental animals demonstrate that activation of AMPK in skeletal muscle protects against insulin resistance, type 2 diabetes and obesity. The regulatory gamma(3) subunit of AMPK is expressed exclusively in skeletal muscle; however, its importance in controlling overall AMPK activity is unknown. While evidence is emerging that gamma subunit mutations interfere specifically with AMP activation, there remains some controversy regarding the impact of gamma subunit mutations. Here we report the first gain-of-function mutation in the muscle-specific regulatory gamma(3) subunit in humans. METHODS AND FINDINGS: We sequenced the exons and splice junctions of the AMPK gamma(3) gene (PRKAG3) in 761 obese and 759 lean individuals, identifying 87 sequence variants including a novel R225W mutation in subjects from two unrelated families. The gamma(3) R225W mutation is homologous in location to the gamma(2)R302Q mutation in patients with Wolf-Parkinson-White syndrome and to the gamma(3)R225Q mutation originally linked to an increase in muscle glycogen content in purebred Hampshire Rendement Napole (RN-) pigs. We demonstrate in differentiated muscle satellite cells obtained from the vastus lateralis of R225W carriers that the mutation is associated with an approximate doubling of both basal and AMP-activated AMPK activities. Moreover, subjects bearing the R225W mutation exhibit a approximately 90% increase of skeletal muscle glycogen content and a approximately 30% decrease in intramuscular triglyceride (IMTG). CONCLUSIONS: We have identified for the first time a mutation in the skeletal muscle-specific regulatory gamma(3) subunit of AMPK in humans. The gamma(3)R225W mutation has significant functional effects as demonstrated by increases in basal and AMP-activated AMPK activities, increased muscle glycogen and decreased IMTG. Overall, these findings are consistent with an important regulatory role for AMPK gamma(3) in human muscle energy metabolism