Drug Transport in Responding Lipid Membranes Can Be Regulated by an External Osmotic Gradient

In this paper, we demonstrate, for the first time, how an external osmotic gradient can be used to regulate diffusion of solutes across a lipid membrane. We present experimental and theoretical studies of the transport of different solutes across a monoolein membrane in the presence of an external osmotic gradient. The osmotic gradient introduces phase transformations in the membrane, and it causes nonlinear transport behavior. The external gradient can thus act as a kind of switch for diffusive transport in the skin and in controlled release drug formulations

The Empty Chair Appointment

The objective was to test an intervention to reduce failed rates for psychiatric appointments. We collected data for this study of the characteristics of patients who missed appointments from March 2011 through September 2012. A phone triage assessment intervention was implemented to address chronic first-time failed attendance appointments (N = 78). The main reason for failed appointments was transportation difficulties. The first-time appointment show rate increased after implementing an assessment intervention. Phone assessment intervention was practical and may improve nonattendance for psychiatric appointments. The discussion reflects speculations about causes and possible measures to make services more accessible

First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

Insights from birthing experiences of fistula survivors in North-central Nigeria: Interplay of structural violence

Obstetric Fistula is an abnormal opening between the vagina and rectum resulting from prolonged and obstructed labour. Studies indicate that delays in accessing maternal care and home birth contribute to the development of fistula. Survivors are usually women of low socioeconomic status residing in rural locations. This study explores the birthing experiences of 15 fistula survivors through a narrative inquiry approach at a repair centre in North-central Nigeria. Using structural violence as a lens, it describes the role of social, political and health systems in the inequitable access to care for women. For women opting for home births, preference for home delivery was mainly due to lack of finances, poor health systems and cultural practices. Rural location inhibited access as, women seeking facility delivery faced transfer delays to referral centres when complications developed. Inequitable maternal health services in rural locations in Nigeria are inherently linked to access to health care; and these contribute to the increased incidences of fistulae. Structural intervention is a health policy priority to address poor health systems and achieve universal health coverage to address maternal health issues in Nigeria

Update on the PACS Polarimeter Data Processing and Algorithm Development

No abstract availabl

The role of the disulfide bond in the interaction of islet amyloid polypeptide with membranes

Human islet amyloid polypeptide (hIAPP) forms amyloid fibrils in pancreatic islets of patients with type 2 diabetes mellitus. It has been suggested that the N-terminal part, which contains a conserved intramolecular disulfide bond between residues 2 and 7, interacts with membranes, ultimately leading to membrane damage and β-cell death. Here, we used variants of the hIAPP1–19 fragment and model membranes of phosphatidylcholine and phosphatidylserine (7:3, molar ratio) to examine the role of this disulfide in membrane interactions. We found that the disulfide bond has a minor effect on membrane insertion properties and peptide conformational behavior, as studied by monolayer techniques, 2H NMR, ThT-fluorescence, membrane leakage, and CD spectroscopy. The results suggest that the disulfide bond does not play a significant role in hIAPP–membrane interactions. Hence, the fact that this bond is conserved is most likely related exclusively to the biological activity of IAPP as a hormone

Self-consistent field theory for the interactions between keratin intermediate filaments

Background: Keratins are important structural proteins found in skin, hair and nails. Keratin Intermediate Filaments are major components of corneocytes, nonviable horny cells of the Stratum Corneum, the outermost layer of skin. It is considered that interactions between unstructured domains of Keratin Intermediate Filaments are the key factor in maintaining the elasticity of the skin. Results: We have developed a model for the interactions between keratin intermediate filaments based on self-consistent field theory. The intermediate filaments are represented by charged surfaces, and the disordered terminal domains of the keratins are represented by charged heteropolymers grafted to these surfaces. We estimate the system is close to a charge compensation point where the heteropolymer grafting density is matched to the surface charge density. Using a protein model with amino acid resolution for the terminal domains, we find that the terminal chains can mediate a weak attraction between the keratin surfaces. The origin of the attraction is a combination of bridging and electrostatics. The attraction disappears when the system moves away from the charge compensation point, or when excess small ions and/or NMF-representing free amino acids are added. Conclusions: These results are in concordance with experimental observations, and support the idea that the interaction between keratin filaments, and ultimately in part the elastic properties of the keratin-containing tissue, is controlled by a combination of the physico-chemical properties of the disordered terminal domains and the composition of the medium in the inter-filament region. Keywords: Stratum corneum, Skin keratins, Intermediate filaments, Unstructured terminal domains, Bridging attractio