304 research outputs found
Inelastic Hadron Diffraction in High Energy Elastic Scattering of Nuclei
The r\^{o}le of inelastic diffraction in elastic scattering of nuclei is
studied in the formalism of \emph{diffractive limit}. The results obtained for
scattering of the --particles on light nuclei show that the nucleonic
diffraction is especially important at large momentum transfers where the
Glauber model of geometric diffraction fails.Comment: 4 pages, 1 figure (in eps) talk given at XXXI International Symposium
on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL
http://ismd31.ccnu.edu.cn
Solvent contribution to the stability of a physical gel characterized by quasi-elastic neutron scattering
The dynamics of a physical gel, namely the Low Molecular Mass Organic Gelator
{\textit Methyl-4,6-O-benzylidene- -D-mannopyranoside (-manno)}
in water and toluene are probed by neutron scattering. Using high gelator
concentrations, we were able to determine, on a timescale from a few ps to 1
ns, the number of solvent molecules that are immobilised by the rigid network
formed by the gelators. We found that only few toluene molecules per gelator
participate to the network which is formed by hydrogen bonding between the
gelators' sugar moieties. In water, however, the interactions leading to the
gel formations are weaker, involving dipolar, hydrophobic or
interactions and hydrogen bonds are formed between the gelators and the
surrounding water. Therefore, around 10 to 14 water molecules per gelator are
immobilised by the presence of the network. This study shows that neutron
scattering can give valuable information about the behaviour of solvent
confined in a molecular gel.Comment: Langmuir (2015
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Motherhood, Moral Authority and the Charismatic Matriarch in the Aftermath of Lethal Violence
Images of maternal suffering are an evocative and powerful means of communication in a world where the private grief of victims has increasingly become subject to commodification and public consumption. This article looks at the influence of bereaved mothers as symbols of respect, peace and dignity in the aftermath of violence, and as a result their persuasive presence in family activism. Drawing upon two case studies, this article explores the importance of victims’ stories in public life and, in particular, the presence of the charismatic matriarch in creating communities of solidarity, raising awareness of harms that have previously gone unheard and prompting policy change. It considers the ‘canonical’ story of the mother in public life and concludes by arguing that more attention should be paid to victims’ stories and their influence on policy-making, politics and eventually in becoming public grievances
Studies of Transonic Aircraft Flows and Prediction of Initial Buffet Onset Using Large-Eddy Simulations
This article utilizes the Large-Eddy Simulation (LES) paradigm with a
physics-based turbulence modeling approach, including a dynamic subgrid-scale
model and an equilibrium wall model, to examine the flow over the NASA
transonic Common Research Model (CRM), a flow configuration that has been the
focus of several AIAA Drag PredictionWorkshops (DPWs). The current work
explores sensitivities to laminar-to-turbulent transition, wind tunnel mounting
system, grid resolution, and grid topology and suggests current best practices
in the context of large-eddy simulations of transonic aircraft flows. It is
found that promoting the flow transition to turbulence via an array of
cylindrical trip dots, including the sting mounting system in the simulations,
and leveraging stranded boundary layer grids all tend to improve the quality of
the LES solutions. Non-monotonic grid convergence in the LES calculations is
observed to be strongly sensitive to grid topology, and stranded meshes rectify
this issue relative to their hexagonal close-packed (HCP) counterparts. The
details of the boundary layer profiles both at the leading edge of the wing and
within the shock-induced separation bubble are studied, with thicknesses and
integral measures reported, providing details about the boundary layer
characteristics to turbulence modelers not typically available from complex
aircraft flows. Finally, an assessment of the initial buffet prediction
capabilities of LES is made in the context of a simpler NACA 0012 flow, with
computational predictions showing reasonable agreement with available
experimental data for the angle of attack at initial buffet onset and shock
oscillation frequency associated with sustained buffet.Comment: Under review for publication consideration in the Journal of Aircraf
Pediacare: A clinic information management system for pediatricians
Abstract onlyTasks of pediatricians is not easy for they have so many appointments to be attended. Secretaries were hired to do the tasks that doctors or pediatricians can’t do. Sometimes clinics cannot accommodate patients for some tasks.
The PediaCare System was develop to help pediatricians make work easier for secretaries, patients, and doctors. Before developing the system, the team conducted interview with at least three clients. The result of the interview were the basis of developing the system to meet the needs of patients, doctor and secretary.
The methodology used in developing the system is the Rapid Application Development (RAD) model. RAD is a development life cycle designed to give much faster development and higher quality system than the traditional life cycle.
The PediaCare System is available for future researchers who might want to propose a relative system, provided that additional features should be added.
The team believes that the system can be a big help to Pediatricians considering the main aspects that affects the storing, gathering of records and other general perspective towards their patient. Service rendered to the patients will be more efficient and systematized.Includes bibliographical referencesBachelor of Science in Information Technolog
Using solution state NMR spectroscopy to probe NMR invisible gelators
Supramolecular hydrogels are formed via the self-assembly of gelator molecules upon application of a suitable trigger. The exact nature of this self-assembly process has been widely investigated as a practical understanding is vital for the informed design of these materials. Solution-state NMR spectroscopy is an excellent non-invasive tool to follow the self-assembly of supramolecular hydrogels. However, in most cases the self-assembled aggregates are silent by conventional 1H NMR spectroscopy due to the low mobility of the constituent molecules, limiting NMR spectroscopy to following only the initial assembly step(s). Here, we present a new solution-state NMR spectroscopic method which allows the entire self-assembly process of a dipeptide gelator to be followed. This gelator forms transparent hydrogels by a multi-stage assembly process when the pH of an initially alkaline solution is lowered via the hydrolysis of glucono-δ-lactone (GdL). Changes in the charge, hydrophobicity and relative arrangement of the supramolecular aggregates can be followed throughout the assembly process by measuring the residual quadrupolar couplings (RQCs) of various molecular probes (here, 14NH4+ and isopropanol-d8), along with the NMR relaxation rates of 23Na+. The initially-formed aggregates comprise negatively charged fibrils which gradually lose their charge and become increasingly hydrophobic as the pH falls, eventually resulting in a macroscopic contraction of the hydrogel. We also demonstrate that the in situ measurement of pH by NMR spectroscopy is both convenient and accurate, representing a useful tool for the characterisation of self-assembly processes by NMR
The Extra Domain A of Fibronectin Increases VEGF-C Expression in Colorectal Carcinoma Involving the PI3K/AKT Signaling Pathway
The extra domain A (EDA)-containing fibronectin (EDA-FN), an alternatively spliced form of the extracellular matrix protein fibronectin, is predominantly expressed in various malignancies but not in normal tissues. In the present study, we investigated the potential pro-lymphangiogenesis effects of extra domain A (EDA)-mediated vascular endothelial growth factor-C (VEGF-C) secretion in colorectal carcinoma (CRC). We detected the expressions of EDA and VEGF-C in 52 human colorectal tumor tissues and their surrounding mucosae by immunohistochemical analysis, and further tested the correlation between the expressions of these two proteins in aforementioned CRC tissues. Both EDA and VEGF-C were abundantly expressed in the specimens of human CRC tissues. And VEGF-C was associated with increased expression of EDA in human CRC according to linear regression analysis. Besides, EDA expression was significantly correlated with lymph node metastasis, tumor differentiation and clinical stage by clinicopathological analysis of tissue microarrays containing tumor tissues of 115 CRC patients. Then, human CRC cell SW480 was transfected with lentivectors to elicit expression of shRNA against EDA (shRNA-EDA), and SW620 was transfected with a lentiviral vector to overexpress EDA (pGC-FU-EDA), respectively. We confirmed that VEGF-C was upregulated in EDA-overexpressed cells, and downregulated in shRNA-EDA cells. Moreover, a PI3K-dependent signaling pathway was found to be involved in EDA-mediated VEGF-C secretion. The in vivo result demonstrated that EDA could promote tumor growth and tumor-induced lymphangiogenesis in mouse xenograft models. Our findings provide evidence that EDA could play a role in tumor-induced lymphangiogenesis via upregulating autocrine secretion of VEGF-C in colorectal cancer, which is associated with the PI3K/Akt-dependent pathway
Metabolic Regulation of Invadopodia and Invasion by Acetyl-CoA Carboxylase 1 and De novo Lipogenesis
Invadopodia are membrane protrusions that facilitate matrix degradation and cellular invasion. Although lipids have been implicated in several aspects of invadopodia formation, the contributions of de novo fatty acid synthesis and lipogenesis have not been defined. Inhibition of acetyl-CoA carboxylase 1 (ACC1), the committed step of fatty acid synthesis, reduced invadopodia formation in Src-transformed 3T3 (3T3-Src) cells, and also decreased the ability to degrade gelatin. Inhibition of fatty acid synthesis through AMP-activated kinase (AMPK) activation and ACC phosphorylation also decreased invadopodia incidence. The addition of exogenous 16∶0 and 18∶1 fatty acid, products of de novo fatty acid synthesis, restored invadopodia and gelatin degradation to cells with decreased ACC1 activity. Pharmacological inhibition of ACC also altered the phospholipid profile of 3T3-Src cells, with the majority of changes occurring in the phosphatidylcholine (PC) species. Exogenous supplementation with the most abundant PC species, 34∶1 PC, restored invadopodia incidence, the ability to degrade gelatin and the ability to invade through matrigel to cells deficient in ACC1 activity. On the other hand, 30∶0 PC did not restore invadopodia and 36∶2 PC only restored invadopodia incidence and gelatin degradation, but not cellular invasion through matrigel. Pharmacological inhibition of ACC also reduced the ability of MDA-MB-231 breast, Snb19 glioblastoma, and PC-3 prostate cancer cells to invade through matrigel. Invasion of PC-3 cells through matrigel was also restored by 34∶1 PC supplementation. Collectively, the data elucidate the novel metabolic regulation of invadopodia and the invasive process by de novo fatty acid synthesis and lipogenesis
Cytoskeletal control of B cell responses to antigens.
The actin cytoskeleton is essential for cell mechanics and has increasingly been implicated in the regulation of cell signalling. In B cells, the actin cytoskeleton is extensively coupled to B cell receptor (BCR) signalling pathways, and defects of the actin cytoskeleton can either promote or suppress B cell activation. Recent insights from studies using single-cell imaging and biophysical techniques suggest that actin orchestrates BCR signalling at the plasma membrane through effects on protein diffusion and that it regulates antigen discrimination through the biomechanics of immune synapses. These mechanical functions also have a role in the adaptation of B cell subsets to specialized tasks during antibody responses
Levels, timing, and etiology of stillbirths in Sylhet district of Bangladesh
<p>Abstract</p> <p>Background</p> <p>Lack of data is a critical barrier to addressing the problem of stillbirth in countries with the highest stillbirth burden. Our study objective was to estimate the levels, types, and causes of stillbirth in rural Sylhet district of Bangladesh.</p> <p>Methods</p> <p>A complete pregnancy history was taken from all women (n = 39 998) who had pregnancy outcomes during 2003-2005 in the study area. Verbal autopsy data were obtained for all identified stillbirths during the period. We used pre-defined case definitions and computer programs to assign causes of stillbirth for selected causes containing specific signs and symptoms. Both non-hierarchical and hierarchical approaches were used to assign causes of stillbirths.</p> <p>Results</p> <p>A total of 1748 stillbirths were recorded during 2003-2005 from 48,192 births (stillbirth rate: 36.3 per 1000 total births). About 60% and 40% of stillbirths were categorized as antepartum and intrapartum, respectively. Maternal conditions, including infections, hypertensive disorders, and anemia, contributed to about 29% of total antepartum stillbirths. About 50% of intrapartum stillbirths were attributed to obstetric complications. Maternal infections and hypertensive disorders contributed to another 11% of stillbirths. A cause could not be assigned in nearly half (49%) of stillbirths.</p> <p>Conclusion</p> <p>The stillbirth rate is high in rural Bangladesh. Based on algorithmic approaches using verbal autopsy data, a substantial portion of stillbirths is attributable to maternal conditions and obstetric complications. Programs need to deliver community-level interventions to prevent and manage maternal complications, and to develop strategies to improve access to emergency obstetric care. Improvements in care to avert stillbirth can be accomplished in the context of existing maternal and child health programs. Methodological improvements in the measurement of stillbirths, especially causes of stillbirths, are also needed to better define the burden of stillbirths in low-resource settings.</p
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